]> code.delx.au - pulseaudio/blobdiff - src/pulsecore/resampler.c
Revert "resampler: Resample first followed by remapping if have more out channels...
[pulseaudio] / src / pulsecore / resampler.c
index b2d512c8de256dddda06e4c6cc4aabcfd621cf82..cdfaf8fa8dcd120ba08076004055bb9f97bc9b9c 100644 (file)
@@ -5,7 +5,7 @@
 
   PulseAudio is free software; you can redistribute it and/or modify
   it under the terms of the GNU Lesser General Public License as published
-  by the Free Software Foundation; either version 2 of the License,
+  by the Free Software Foundation; either version 2.1 of the License,
   or (at your option) any later version.
 
   PulseAudio is distributed in the hope that it will be useful, but
 
 #include <string.h>
 
-#if HAVE_LIBSAMPLERATE
+#ifdef HAVE_LIBSAMPLERATE
 #include <samplerate.h>
 #endif
 
+#ifdef HAVE_SPEEX
 #include <speex/speex_resampler.h>
-
-#include <liboil/liboilfuncs.h>
-#include <liboil/liboil.h>
+#endif
 
 #include <pulse/xmalloc.h>
 #include <pulsecore/sconv.h>
 #include <pulsecore/log.h>
 #include <pulsecore/macro.h>
 #include <pulsecore/strbuf.h>
-
+#include <pulsecore/remap.h>
+#include <pulsecore/core-util.h>
 #include "ffmpeg/avcodec.h"
 
 #include "resampler.h"
@@ -56,16 +56,23 @@ struct pa_resampler {
     size_t i_fz, o_fz, w_sz;
     pa_mempool *mempool;
 
-    pa_memchunk buf1, buf2, buf3, buf4;
-    unsigned buf1_samples, buf2_samples, buf3_samples, buf4_samples;
+    pa_memchunk to_work_format_buf;
+    pa_memchunk remap_buf;
+    pa_memchunk resample_buf;
+    pa_memchunk from_work_format_buf;
+    unsigned to_work_format_buf_samples;
+    size_t remap_buf_size;
+    unsigned resample_buf_samples;
+    unsigned from_work_format_buf_samples;
+    bool remap_buf_contains_leftover_data;
 
     pa_sample_format_t work_format;
 
     pa_convert_func_t to_work_format_func;
     pa_convert_func_t from_work_format_func;
 
-    float map_table[PA_CHANNELS_MAX][PA_CHANNELS_MAX];
-    pa_bool_t map_required;
+    pa_remap_t remap;
+    bool map_required;
 
     void (*impl_free)(pa_resampler *r);
     void (*impl_update_rates)(pa_resampler *r);
@@ -92,9 +99,11 @@ struct pa_resampler {
     } src;
 #endif
 
+#ifdef HAVE_SPEEX
     struct { /* data specific to speex */
         SpeexResamplerState* state;
     } speex;
+#endif
 
     struct { /* data specific to ffmpeg */
         struct AVResampleContext *state;
@@ -104,7 +113,9 @@ struct pa_resampler {
 
 static int copy_init(pa_resampler *r);
 static int trivial_init(pa_resampler*r);
+#ifdef HAVE_SPEEX
 static int speex_init(pa_resampler*r);
+#endif
 static int ffmpeg_init(pa_resampler*r);
 static int peaks_init(pa_resampler*r);
 #ifdef HAVE_LIBSAMPLERATE
@@ -128,6 +139,7 @@ static int (* const init_table[])(pa_resampler*r) = {
     [PA_RESAMPLER_SRC_LINEAR]              = NULL,
 #endif
     [PA_RESAMPLER_TRIVIAL]                 = trivial_init,
+#ifdef HAVE_SPEEX
     [PA_RESAMPLER_SPEEX_FLOAT_BASE+0]      = speex_init,
     [PA_RESAMPLER_SPEEX_FLOAT_BASE+1]      = speex_init,
     [PA_RESAMPLER_SPEEX_FLOAT_BASE+2]      = speex_init,
@@ -150,22 +162,36 @@ static int (* const init_table[])(pa_resampler*r) = {
     [PA_RESAMPLER_SPEEX_FIXED_BASE+8]      = speex_init,
     [PA_RESAMPLER_SPEEX_FIXED_BASE+9]      = speex_init,
     [PA_RESAMPLER_SPEEX_FIXED_BASE+10]     = speex_init,
+#else
+    [PA_RESAMPLER_SPEEX_FLOAT_BASE+0]      = NULL,
+    [PA_RESAMPLER_SPEEX_FLOAT_BASE+1]      = NULL,
+    [PA_RESAMPLER_SPEEX_FLOAT_BASE+2]      = NULL,
+    [PA_RESAMPLER_SPEEX_FLOAT_BASE+3]      = NULL,
+    [PA_RESAMPLER_SPEEX_FLOAT_BASE+4]      = NULL,
+    [PA_RESAMPLER_SPEEX_FLOAT_BASE+5]      = NULL,
+    [PA_RESAMPLER_SPEEX_FLOAT_BASE+6]      = NULL,
+    [PA_RESAMPLER_SPEEX_FLOAT_BASE+7]      = NULL,
+    [PA_RESAMPLER_SPEEX_FLOAT_BASE+8]      = NULL,
+    [PA_RESAMPLER_SPEEX_FLOAT_BASE+9]      = NULL,
+    [PA_RESAMPLER_SPEEX_FLOAT_BASE+10]     = NULL,
+    [PA_RESAMPLER_SPEEX_FIXED_BASE+0]      = NULL,
+    [PA_RESAMPLER_SPEEX_FIXED_BASE+1]      = NULL,
+    [PA_RESAMPLER_SPEEX_FIXED_BASE+2]      = NULL,
+    [PA_RESAMPLER_SPEEX_FIXED_BASE+3]      = NULL,
+    [PA_RESAMPLER_SPEEX_FIXED_BASE+4]      = NULL,
+    [PA_RESAMPLER_SPEEX_FIXED_BASE+5]      = NULL,
+    [PA_RESAMPLER_SPEEX_FIXED_BASE+6]      = NULL,
+    [PA_RESAMPLER_SPEEX_FIXED_BASE+7]      = NULL,
+    [PA_RESAMPLER_SPEEX_FIXED_BASE+8]      = NULL,
+    [PA_RESAMPLER_SPEEX_FIXED_BASE+9]      = NULL,
+    [PA_RESAMPLER_SPEEX_FIXED_BASE+10]     = NULL,
+#endif
     [PA_RESAMPLER_FFMPEG]                  = ffmpeg_init,
     [PA_RESAMPLER_AUTO]                    = NULL,
     [PA_RESAMPLER_COPY]                    = copy_init,
     [PA_RESAMPLER_PEAKS]                   = peaks_init,
 };
 
-static inline size_t sample_size(pa_sample_format_t f) {
-    pa_sample_spec ss = {
-        .format = f,
-        .rate = 0,
-        .channels = 1
-    };
-
-    return pa_sample_size(&ss);
-}
-
 pa_resampler* pa_resampler_new(
         pa_mempool *pool,
         const pa_sample_spec *a,
@@ -207,23 +233,31 @@ pa_resampler* pa_resampler_new(
         method = PA_RESAMPLER_AUTO;
     }
 
-    if (method == PA_RESAMPLER_AUTO)
-        method = PA_RESAMPLER_SPEEX_FLOAT_BASE + 3;
+    if (method == PA_RESAMPLER_AUTO) {
+#ifdef HAVE_SPEEX
+        method = PA_RESAMPLER_SPEEX_FLOAT_BASE + 1;
+#else
+        if (flags & PA_RESAMPLER_VARIABLE_RATE)
+            method = PA_RESAMPLER_TRIVIAL;
+        else
+            method = PA_RESAMPLER_FFMPEG;
+#endif
+    }
 
-    r = pa_xnew(pa_resampler, 1);
+    r = pa_xnew0(pa_resampler, 1);
     r->mempool = pool;
     r->method = method;
     r->flags = flags;
 
-    r->impl_free = NULL;
-    r->impl_update_rates = NULL;
-    r->impl_resample = NULL;
-    r->impl_reset = NULL;
-
     /* Fill sample specs */
     r->i_ss = *a;
     r->o_ss = *b;
 
+    /* set up the remap structure */
+    r->remap.i_ss = &r->i_ss;
+    r->remap.o_ss = &r->o_ss;
+    r->remap.format = &r->work_format;
+
     if (am)
         r->i_cm = *am;
     else if (!pa_channel_map_init_auto(&r->i_cm, r->i_ss.channels, PA_CHANNEL_MAP_DEFAULT))
@@ -237,13 +271,6 @@ pa_resampler* pa_resampler_new(
     r->i_fz = pa_frame_size(a);
     r->o_fz = pa_frame_size(b);
 
-    pa_memchunk_reset(&r->buf1);
-    pa_memchunk_reset(&r->buf2);
-    pa_memchunk_reset(&r->buf3);
-    pa_memchunk_reset(&r->buf4);
-
-    r->buf1_samples = r->buf2_samples = r->buf3_samples = r->buf4_samples = 0;
-
     calc_map_table(r);
 
     pa_log_info("Using resampler '%s'", pa_resample_method_to_string(method));
@@ -255,10 +282,16 @@ pa_resampler* pa_resampler_new(
 
         if (r->map_required || a->format != b->format || method == PA_RESAMPLER_PEAKS) {
 
-            if (a->format == PA_SAMPLE_S32NE || a->format == PA_SAMPLE_S32RE ||
+            if (a->format == PA_SAMPLE_S16NE || b->format == PA_SAMPLE_S16NE)
+                r->work_format = PA_SAMPLE_S16NE;
+            else if (a->format == PA_SAMPLE_S32NE || a->format == PA_SAMPLE_S32RE ||
                 a->format == PA_SAMPLE_FLOAT32NE || a->format == PA_SAMPLE_FLOAT32RE ||
+                a->format == PA_SAMPLE_S24NE || a->format == PA_SAMPLE_S24RE ||
+                a->format == PA_SAMPLE_S24_32NE || a->format == PA_SAMPLE_S24_32RE ||
                 b->format == PA_SAMPLE_S32NE || b->format == PA_SAMPLE_S32RE ||
-                b->format == PA_SAMPLE_FLOAT32NE || b->format == PA_SAMPLE_FLOAT32RE)
+                b->format == PA_SAMPLE_FLOAT32NE || b->format == PA_SAMPLE_FLOAT32RE ||
+                b->format == PA_SAMPLE_S24NE || b->format == PA_SAMPLE_S24RE ||
+                b->format == PA_SAMPLE_S24_32NE || b->format == PA_SAMPLE_S24_32RE)
                 r->work_format = PA_SAMPLE_FLOAT32NE;
             else
                 r->work_format = PA_SAMPLE_S16NE;
@@ -271,28 +304,28 @@ pa_resampler* pa_resampler_new(
 
     pa_log_info("Using %s as working format.", pa_sample_format_to_string(r->work_format));
 
-    r->w_sz = sample_size(r->work_format);
+    r->w_sz = pa_sample_size_of_format(r->work_format);
 
-    if (r->i_ss.format == r->work_format)
-        r->to_work_format_func = NULL;
-    else if (r->work_format == PA_SAMPLE_FLOAT32NE) {
-        if (!(r->to_work_format_func = pa_get_convert_to_float32ne_function(r->i_ss.format)))
-            goto fail;
-    } else {
-        pa_assert(r->work_format == PA_SAMPLE_S16NE);
-        if (!(r->to_work_format_func = pa_get_convert_to_s16ne_function(r->i_ss.format)))
-            goto fail;
+    if (r->i_ss.format != r->work_format) {
+        if (r->work_format == PA_SAMPLE_FLOAT32NE) {
+            if (!(r->to_work_format_func = pa_get_convert_to_float32ne_function(r->i_ss.format)))
+                goto fail;
+        } else {
+            pa_assert(r->work_format == PA_SAMPLE_S16NE);
+            if (!(r->to_work_format_func = pa_get_convert_to_s16ne_function(r->i_ss.format)))
+                goto fail;
+        }
     }
 
-    if (r->o_ss.format == r->work_format)
-        r->from_work_format_func = NULL;
-    else if (r->work_format == PA_SAMPLE_FLOAT32NE) {
-        if (!(r->from_work_format_func = pa_get_convert_from_float32ne_function(r->o_ss.format)))
-            goto fail;
-    } else {
-        pa_assert(r->work_format == PA_SAMPLE_S16NE);
-        if (!(r->from_work_format_func = pa_get_convert_from_s16ne_function(r->o_ss.format)))
-            goto fail;
+    if (r->o_ss.format != r->work_format) {
+        if (r->work_format == PA_SAMPLE_FLOAT32NE) {
+            if (!(r->from_work_format_func = pa_get_convert_from_float32ne_function(r->o_ss.format)))
+                goto fail;
+        } else {
+            pa_assert(r->work_format == PA_SAMPLE_S16NE);
+            if (!(r->from_work_format_func = pa_get_convert_from_s16ne_function(r->o_ss.format)))
+                goto fail;
+        }
     }
 
     /* initialize implementation */
@@ -302,8 +335,7 @@ pa_resampler* pa_resampler_new(
     return r;
 
 fail:
-    if (r)
-        pa_xfree(r);
+    pa_xfree(r);
 
     return NULL;
 }
@@ -314,14 +346,14 @@ void pa_resampler_free(pa_resampler *r) {
     if (r->impl_free)
         r->impl_free(r);
 
-    if (r->buf1.memblock)
-        pa_memblock_unref(r->buf1.memblock);
-    if (r->buf2.memblock)
-        pa_memblock_unref(r->buf2.memblock);
-    if (r->buf3.memblock)
-        pa_memblock_unref(r->buf3.memblock);
-    if (r->buf4.memblock)
-        pa_memblock_unref(r->buf4.memblock);
+    if (r->to_work_format_buf.memblock)
+        pa_memblock_unref(r->to_work_format_buf.memblock);
+    if (r->remap_buf.memblock)
+        pa_memblock_unref(r->remap_buf.memblock);
+    if (r->resample_buf.memblock)
+        pa_memblock_unref(r->resample_buf.memblock);
+    if (r->from_work_format_buf.memblock)
+        pa_memblock_unref(r->from_work_format_buf.memblock);
 
     pa_xfree(r);
 }
@@ -353,19 +385,39 @@ void pa_resampler_set_output_rate(pa_resampler *r, uint32_t rate) {
 size_t pa_resampler_request(pa_resampler *r, size_t out_length) {
     pa_assert(r);
 
-    return (((out_length / r->o_fz)*r->i_ss.rate)/r->o_ss.rate) * r->i_fz;
+    /* Let's round up here to make it more likely that the caller will get at
+     * least out_length amount of data from pa_resampler_run().
+     *
+     * We don't take the leftover into account here. If we did, then it might
+     * be in theory possible that this function would return 0 and
+     * pa_resampler_run() would also return 0. That could lead to infinite
+     * loops. When the leftover is ignored here, such loops would eventually
+     * terminate, because the leftover would grow each round, finally
+     * surpassing the minimum input threshold of the resampler. */
+    return ((((uint64_t) ((out_length + r->o_fz-1) / r->o_fz) * r->i_ss.rate) + r->o_ss.rate-1) / r->o_ss.rate) * r->i_fz;
 }
 
 size_t pa_resampler_result(pa_resampler *r, size_t in_length) {
+    size_t frames;
+
     pa_assert(r);
 
-    return (((in_length / r->i_fz)*r->o_ss.rate)/r->i_ss.rate) * r->o_fz;
+    /* Let's round up here to ensure that the caller will always allocate big
+     * enough output buffer. */
+
+    frames = (in_length + r->i_fz - 1) / r->i_fz;
+
+    if (r->remap_buf_contains_leftover_data)
+        frames += r->remap_buf.length / (r->w_sz * r->o_ss.channels);
+
+    return (((uint64_t) frames * r->o_ss.rate + r->i_ss.rate - 1) / r->i_ss.rate) * r->o_fz;
 }
 
 size_t pa_resampler_max_block_size(pa_resampler *r) {
     size_t block_size_max;
-    pa_sample_spec ss;
-    size_t fs;
+    pa_sample_spec max_ss;
+    size_t max_fs;
+    size_t frames;
 
     pa_assert(r);
 
@@ -373,17 +425,21 @@ size_t pa_resampler_max_block_size(pa_resampler *r) {
 
     /* We deduce the "largest" sample spec we're using during the
      * conversion */
-    ss.channels = (uint8_t) (PA_MAX(r->i_ss.channels, r->o_ss.channels));
+    max_ss.channels = (uint8_t) (PA_MAX(r->i_ss.channels, r->o_ss.channels));
 
     /* We silently assume that the format enum is ordered by size */
-    ss.format = PA_MAX(r->i_ss.format, r->o_ss.format);
-    ss.format = PA_MAX(ss.format, r->work_format);
+    max_ss.format = PA_MAX(r->i_ss.format, r->o_ss.format);
+    max_ss.format = PA_MAX(max_ss.format, r->work_format);
 
-    ss.rate = PA_MAX(r->i_ss.rate, r->o_ss.rate);
+    max_ss.rate = PA_MAX(r->i_ss.rate, r->o_ss.rate);
 
-    fs = pa_frame_size(&ss);
+    max_fs = pa_frame_size(&max_ss);
+    frames = block_size_max / max_fs - EXTRA_FRAMES;
 
-    return (((block_size_max/fs - EXTRA_FRAMES)*r->i_ss.rate)/ss.rate)*r->i_fz;
+    if (r->remap_buf_contains_leftover_data)
+        frames -= r->remap_buf.length / (r->w_sz * r->o_ss.channels);
+
+    return ((uint64_t) frames * r->i_ss.rate / max_ss.rate) * r->i_fz;
 }
 
 void pa_resampler_reset(pa_resampler *r) {
@@ -391,6 +447,8 @@ void pa_resampler_reset(pa_resampler *r) {
 
     if (r->impl_reset)
         r->impl_reset(r);
+
+    r->remap_buf_contains_leftover_data = false;
 }
 
 pa_resample_method_t pa_resampler_get_method(pa_resampler *r) {
@@ -399,6 +457,30 @@ pa_resample_method_t pa_resampler_get_method(pa_resampler *r) {
     return r->method;
 }
 
+const pa_channel_map* pa_resampler_input_channel_map(pa_resampler *r) {
+    pa_assert(r);
+
+    return &r->i_cm;
+}
+
+const pa_sample_spec* pa_resampler_input_sample_spec(pa_resampler *r) {
+    pa_assert(r);
+
+    return &r->i_ss;
+}
+
+const pa_channel_map* pa_resampler_output_channel_map(pa_resampler *r) {
+    pa_assert(r);
+
+    return &r->o_cm;
+}
+
+const pa_sample_spec* pa_resampler_output_sample_spec(pa_resampler *r) {
+    pa_assert(r);
+
+    return &r->o_ss;
+}
+
 static const char * const resample_methods[] = {
     "src-sinc-best-quality",
     "src-sinc-medium-quality",
@@ -452,6 +534,13 @@ int pa_resample_method_supported(pa_resample_method_t m) {
         return 0;
 #endif
 
+#ifndef HAVE_SPEEX
+    if (m >= PA_RESAMPLER_SPEEX_FLOAT_BASE && m <= PA_RESAMPLER_SPEEX_FLOAT_MAX)
+        return 0;
+    if (m >= PA_RESAMPLER_SPEEX_FIXED_BASE && m <= PA_RESAMPLER_SPEEX_FIXED_MAX)
+        return 0;
+#endif
+
     return 1;
 }
 
@@ -461,19 +550,19 @@ pa_resample_method_t pa_parse_resample_method(const char *string) {
     pa_assert(string);
 
     for (m = 0; m < PA_RESAMPLER_MAX; m++)
-        if (!strcmp(string, resample_methods[m]))
+        if (pa_streq(string, resample_methods[m]))
             return m;
 
-    if (!strcmp(string, "speex-fixed"))
-        return PA_RESAMPLER_SPEEX_FIXED_BASE + 3;
+    if (pa_streq(string, "speex-fixed"))
+        return PA_RESAMPLER_SPEEX_FIXED_BASE + 1;
 
-    if (!strcmp(string, "speex-float"))
-        return PA_RESAMPLER_SPEEX_FLOAT_BASE + 3;
+    if (pa_streq(string, "speex-float"))
+        return PA_RESAMPLER_SPEEX_FLOAT_BASE + 1;
 
     return PA_RESAMPLER_INVALID;
 }
 
-static pa_bool_t on_left(pa_channel_position_t p) {
+static bool on_left(pa_channel_position_t p) {
 
     return
         p == PA_CHANNEL_POSITION_FRONT_LEFT ||
@@ -484,7 +573,7 @@ static pa_bool_t on_left(pa_channel_position_t p) {
         p == PA_CHANNEL_POSITION_TOP_REAR_LEFT;
 }
 
-static pa_bool_t on_right(pa_channel_position_t p) {
+static bool on_right(pa_channel_position_t p) {
 
     return
         p == PA_CHANNEL_POSITION_FRONT_RIGHT ||
@@ -495,7 +584,7 @@ static pa_bool_t on_right(pa_channel_position_t p) {
         p == PA_CHANNEL_POSITION_TOP_REAR_RIGHT;
 }
 
-static pa_bool_t on_center(pa_channel_position_t p) {
+static bool on_center(pa_channel_position_t p) {
 
     return
         p == PA_CHANNEL_POSITION_FRONT_CENTER ||
@@ -505,238 +594,284 @@ static pa_bool_t on_center(pa_channel_position_t p) {
         p == PA_CHANNEL_POSITION_TOP_REAR_CENTER;
 }
 
-static pa_bool_t on_lfe(pa_channel_position_t p) {
+static bool on_lfe(pa_channel_position_t p) {
     return
         p == PA_CHANNEL_POSITION_LFE;
 }
 
+static bool on_front(pa_channel_position_t p) {
+    return
+        p == PA_CHANNEL_POSITION_FRONT_LEFT ||
+        p == PA_CHANNEL_POSITION_FRONT_RIGHT ||
+        p == PA_CHANNEL_POSITION_FRONT_CENTER ||
+        p == PA_CHANNEL_POSITION_TOP_FRONT_LEFT ||
+        p == PA_CHANNEL_POSITION_TOP_FRONT_RIGHT ||
+        p == PA_CHANNEL_POSITION_TOP_FRONT_CENTER ||
+        p == PA_CHANNEL_POSITION_FRONT_LEFT_OF_CENTER ||
+        p == PA_CHANNEL_POSITION_FRONT_RIGHT_OF_CENTER;
+}
+
+static bool on_rear(pa_channel_position_t p) {
+    return
+        p == PA_CHANNEL_POSITION_REAR_LEFT ||
+        p == PA_CHANNEL_POSITION_REAR_RIGHT ||
+        p == PA_CHANNEL_POSITION_REAR_CENTER ||
+        p == PA_CHANNEL_POSITION_TOP_REAR_LEFT ||
+        p == PA_CHANNEL_POSITION_TOP_REAR_RIGHT ||
+        p == PA_CHANNEL_POSITION_TOP_REAR_CENTER;
+}
+
+static bool on_side(pa_channel_position_t p) {
+    return
+        p == PA_CHANNEL_POSITION_SIDE_LEFT ||
+        p == PA_CHANNEL_POSITION_SIDE_RIGHT ||
+        p == PA_CHANNEL_POSITION_TOP_CENTER;
+}
+
+enum {
+    ON_FRONT,
+    ON_REAR,
+    ON_SIDE,
+    ON_OTHER
+};
+
+static int front_rear_side(pa_channel_position_t p) {
+    if (on_front(p))
+        return ON_FRONT;
+    if (on_rear(p))
+        return ON_REAR;
+    if (on_side(p))
+        return ON_SIDE;
+    return ON_OTHER;
+}
+
 static void calc_map_table(pa_resampler *r) {
     unsigned oc, ic;
-    pa_bool_t ic_connected[PA_CHANNELS_MAX];
-    pa_bool_t remix;
+    unsigned n_oc, n_ic;
+    bool ic_connected[PA_CHANNELS_MAX];
+    bool remix;
     pa_strbuf *s;
     char *t;
+    pa_remap_t *m;
 
     pa_assert(r);
 
     if (!(r->map_required = (r->i_ss.channels != r->o_ss.channels || (!(r->flags & PA_RESAMPLER_NO_REMAP) && !pa_channel_map_equal(&r->i_cm, &r->o_cm)))))
         return;
 
-    memset(r->map_table, 0, sizeof(r->map_table));
+    m = &r->remap;
+
+    n_oc = r->o_ss.channels;
+    n_ic = r->i_ss.channels;
+
+    memset(m->map_table_f, 0, sizeof(m->map_table_f));
+    memset(m->map_table_i, 0, sizeof(m->map_table_i));
+
     memset(ic_connected, 0, sizeof(ic_connected));
-    remix = (r->flags & (PA_RESAMPLER_NO_REMAP|PA_RESAMPLER_NO_REMIX)) == 0;
+    remix = (r->flags & (PA_RESAMPLER_NO_REMAP | PA_RESAMPLER_NO_REMIX)) == 0;
 
-    for (oc = 0; oc < r->o_ss.channels; oc++) {
-        pa_bool_t oc_connected = FALSE;
-        pa_channel_position_t b = r->o_cm.map[oc];
+    if (r->flags & PA_RESAMPLER_NO_REMAP) {
+        pa_assert(!remix);
 
-        for (ic = 0; ic < r->i_ss.channels; ic++) {
-            pa_channel_position_t a = r->i_cm.map[ic];
+        for (oc = 0; oc < PA_MIN(n_ic, n_oc); oc++)
+            m->map_table_f[oc][oc] = 1.0f;
 
-            if (r->flags & PA_RESAMPLER_NO_REMAP) {
-                /* We shall not do any remapping. Hence, just check by index */
+    } else if (r->flags & PA_RESAMPLER_NO_REMIX) {
+        pa_assert(!remix);
+        for (oc = 0; oc < n_oc; oc++) {
+            pa_channel_position_t b = r->o_cm.map[oc];
 
-                if (ic == oc)
-                    r->map_table[oc][ic] = 1.0;
+            for (ic = 0; ic < n_ic; ic++) {
+                pa_channel_position_t a = r->i_cm.map[ic];
 
-                continue;
+                /* We shall not do any remixing. Hence, just check by name */
+                if (a == b)
+                    m->map_table_f[oc][ic] = 1.0f;
             }
+        }
+    } else {
 
-            if (r->flags & PA_RESAMPLER_NO_REMIX) {
-                /* We shall not do any remixing. Hence, just check by name */
+        /* OK, we shall do the full monty: upmixing and downmixing. Our
+         * algorithm is relatively simple, does not do spacialization, delay
+         * elements or apply lowpass filters for LFE. Patches are always
+         * welcome, though. Oh, and it doesn't do any matrix decoding. (Which
+         * probably wouldn't make any sense anyway.)
+         *
+         * This code is not idempotent: downmixing an upmixed stereo stream is
+         * not identical to the original. The volume will not match, and the
+         * two channels will be a linear combination of both.
+         *
+         * This is loosely based on random suggestions found on the Internet,
+         * such as this:
+         * http://www.halfgaar.net/surround-sound-in-linux and the alsa upmix
+         * plugin.
+         *
+         * The algorithm works basically like this:
+         *
+         * 1) Connect all channels with matching names.
+         *
+         * 2) Mono Handling:
+         *    S:Mono: Copy into all D:channels
+         *    D:Mono: Avg all S:channels
+         *
+         * 3) Mix D:Left, D:Right:
+         *    D:Left: If not connected, avg all S:Left
+         *    D:Right: If not connected, avg all S:Right
+         *
+         * 4) Mix D:Center
+         *    If not connected, avg all S:Center
+         *    If still not connected, avg all S:Left, S:Right
+         *
+         * 5) Mix D:LFE
+         *    If not connected, avg all S:*
+         *
+         * 6) Make sure S:Left/S:Right is used: S:Left/S:Right: If not
+         *    connected, mix into all D:left and all D:right channels. Gain is
+         *    1/9.
+         *
+         * 7) Make sure S:Center, S:LFE is used:
+         *
+         *    S:Center, S:LFE: If not connected, mix into all D:left, all
+         *    D:right, all D:center channels. Gain is 0.5 for center and 0.375
+         *    for LFE. C-front is only mixed into L-front/R-front if available,
+         *    otherwise into all L/R channels. Similarly for C-rear.
+         *
+         * 8) Normalize each row in the matrix such that the sum for each row is
+         *    not larger than 1.0 in order to avoid clipping.
+         *
+         * S: and D: shall relate to the source resp. destination channels.
+         *
+         * Rationale: 1, 2 are probably obvious. For 3: this copies front to
+         * rear if needed. For 4: we try to find some suitable C source for C,
+         * if we don't find any, we avg L and R. For 5: LFE is mixed from all
+         * channels. For 6: the rear channels should not be dropped entirely,
+         * however have only minimal impact. For 7: movies usually encode
+         * speech on the center channel. Thus we have to make sure this channel
+         * is distributed to L and R if not available in the output. Also, LFE
+         * is used to achieve a greater dynamic range, and thus we should try
+         * to do our best to pass it to L+R.
+         */
 
-                if (a == b)
-                    r->map_table[oc][ic] = 1.0;
+        unsigned
+            ic_left = 0,
+            ic_right = 0,
+            ic_center = 0,
+            ic_unconnected_left = 0,
+            ic_unconnected_right = 0,
+            ic_unconnected_center = 0,
+            ic_unconnected_lfe = 0;
+        bool ic_unconnected_center_mixed_in = 0;
 
-                continue;
-            }
+        pa_assert(remix);
 
-            pa_assert(remix);
-
-            /* OK, we shall do the full monty: upmixing and
-             * downmixing. Our algorithm is relatively simple, does
-             * not do spacialization, delay elements or apply lowpass
-             * filters for LFE. Patches are always welcome,
-             * though. Oh, and it doesn't do any matrix
-             * decoding. (Which probably wouldn't make any sense
-             * anyway.)
-             *
-             * This code is not idempotent: downmixing an upmixed
-             * stereo stream is not identical to the original. The
-             * volume will not match, and the two channels will be a
-             * linear combination of both.
-             *
-             * This is losely based on random suggestions found on the
-             * Internet, such as this:
-             * http://www.halfgaar.net/surround-sound-in-linux and the
-             * alsa upmix plugin.
-             *
-             * The algorithm works basically like this:
-             *
-             * 1) Connect all channels with matching names.
-             *
-             * 2) Mono Handling:
-             *    S:Mono: Copy into all D:channels
-             *    D:Mono: Copy in all S:channels
-             *
-             * 3) Mix D:Left, D:Right:
-             *    D:Left: If not connected, avg all S:Left
-             *    D:Right: If not connected, avg all S:Right
-             *
-             * 4) Mix D:Center
-             *       If not connected, avg all S:Center
-             *       If still not connected, avg all S:Left, S:Right
-             *
-             * 5) Mix D:LFE
-             *       If not connected, avg all S:*
-             *
-             * 6) Make sure S:Left/S:Right is used: S:Left/S:Right: If
-             *    not connected, mix into all D:left and all D:right
-             *    channels. Gain is 0.1, the current left and right
-             *    should be multiplied by 0.9.
-             *
-             * 7) Make sure S:Center, S:LFE is used:
-             *
-             *    S:Center, S:LFE: If not connected, mix into all
-             *    D:left, all D:right, all D:center channels, gain is
-             *    0.375. The current (as result of 1..6) factors
-             *    should be multiplied by 0.75. (Alt. suggestion: 0.25
-             *    vs. 0.5)
-             *
-             * S: and D: shall relate to the source resp. destination channels.
-             *
-             * Rationale: 1, 2 are probably obvious. For 3: this
-             * copies front to rear if needed. For 4: we try to find
-             * some suitable C source for C, if we don't find any, we
-             * avg L and R. For 5: LFE is mixed from all channels. For
-             * 6: the rear channels should not be dropped entirely,
-             * however have only minimal impact. For 7: movies usually
-             * encode speech on the center channel. Thus we have to
-             * make sure this channel is distributed to L and R if not
-             * available in the output. Also, LFE is used to achieve a
-             * greater dynamic range, and thus we should try to do our
-             * best to pass it to L+R.
-             */
-
-            if (a == b || a == PA_CHANNEL_POSITION_MONO || b == PA_CHANNEL_POSITION_MONO) {
-                r->map_table[oc][ic] = 1.0;
-
-                oc_connected = TRUE;
-                ic_connected[ic] = TRUE;
-            }
+        for (ic = 0; ic < n_ic; ic++) {
+            if (on_left(r->i_cm.map[ic]))
+                ic_left++;
+            if (on_right(r->i_cm.map[ic]))
+                ic_right++;
+            if (on_center(r->i_cm.map[ic]))
+                ic_center++;
         }
 
-        if (!oc_connected && remix) {
-            /* OK, we shall remix */
+        for (oc = 0; oc < n_oc; oc++) {
+            bool oc_connected = false;
+            pa_channel_position_t b = r->o_cm.map[oc];
 
-            if (on_left(b)) {
-                unsigned n = 0;
+            for (ic = 0; ic < n_ic; ic++) {
+                pa_channel_position_t a = r->i_cm.map[ic];
 
-                /* We are not connected and on the left side, let's
-                 * average all left side input channels. */
+                if (a == b || a == PA_CHANNEL_POSITION_MONO) {
+                    m->map_table_f[oc][ic] = 1.0f;
 
-                for (ic = 0; ic < r->i_ss.channels; ic++)
-                    if (on_left(r->i_cm.map[ic]))
-                        n++;
+                    oc_connected = true;
+                    ic_connected[ic] = true;
+                }
+                else if (b == PA_CHANNEL_POSITION_MONO) {
+                    m->map_table_f[oc][ic] = 1.0f / (float) n_ic;
 
-                if (n > 0)
-                    for (ic = 0; ic < r->i_ss.channels; ic++)
-                        if (on_left(r->i_cm.map[ic])) {
-                            r->map_table[oc][ic] = 1.0f / (float) n;
-                            ic_connected[ic] = TRUE;
-                        }
+                    oc_connected = true;
+                    ic_connected[ic] = true;
+                }
+            }
 
-                /* We ignore the case where there is no left input
-                 * channel. Something is really wrong in this case
-                 * anyway. */
+            if (!oc_connected) {
+                /* Try to find matching input ports for this output port */
 
-            } else if (on_right(b)) {
-                unsigned n = 0;
+                if (on_left(b)) {
 
-                /* We are not connected and on the right side, let's
-                 * average all right side input channels. */
+                    /* We are not connected and on the left side, let's
+                     * average all left side input channels. */
 
-                for (ic = 0; ic < r->i_ss.channels; ic++)
-                    if (on_right(r->i_cm.map[ic]))
-                        n++;
+                    if (ic_left > 0)
+                        for (ic = 0; ic < n_ic; ic++)
+                            if (on_left(r->i_cm.map[ic])) {
+                                m->map_table_f[oc][ic] = 1.0f / (float) ic_left;
+                                ic_connected[ic] = true;
+                            }
 
-                if (n > 0)
-                    for (ic = 0; ic < r->i_ss.channels; ic++)
-                        if (on_right(r->i_cm.map[ic])) {
-                            r->map_table[oc][ic] = 1.0f / (float) n;
-                            ic_connected[ic] = TRUE;
-                        }
+                    /* We ignore the case where there is no left input channel.
+                     * Something is really wrong in this case anyway. */
 
-                /* We ignore the case where there is no right input
-                 * channel. Something is really wrong in this case
-                 * anyway. */
+                } else if (on_right(b)) {
 
-            } else if (on_center(b)) {
-                unsigned n = 0;
+                    /* We are not connected and on the right side, let's
+                     * average all right side input channels. */
 
-                /* We are not connected and at the center. Let's
-                 * average all center input channels. */
+                    if (ic_right > 0)
+                        for (ic = 0; ic < n_ic; ic++)
+                            if (on_right(r->i_cm.map[ic])) {
+                                m->map_table_f[oc][ic] = 1.0f / (float) ic_right;
+                                ic_connected[ic] = true;
+                            }
+
+                    /* We ignore the case where there is no right input
+                     * channel. Something is really wrong in this case anyway.
+                     * */
 
-                for (ic = 0; ic < r->i_ss.channels; ic++)
-                    if (on_center(r->i_cm.map[ic]))
-                        n++;
+                } else if (on_center(b)) {
 
-                if (n > 0) {
-                    for (ic = 0; ic < r->i_ss.channels; ic++)
-                        if (on_center(r->i_cm.map[ic])) {
-                            r->map_table[oc][ic] = 1.0f / (float) n;
-                            ic_connected[ic] = TRUE;
-                        }
-                } else {
+                    if (ic_center > 0) {
 
-                    /* Hmm, no center channel around, let's synthesize
-                     * it by mixing L and R.*/
+                        /* We are not connected and at the center. Let's average
+                         * all center input channels. */
+
+                        for (ic = 0; ic < n_ic; ic++)
+                            if (on_center(r->i_cm.map[ic])) {
+                                m->map_table_f[oc][ic] = 1.0f / (float) ic_center;
+                                ic_connected[ic] = true;
+                            }
 
-                    n = 0;
+                    } else if (ic_left + ic_right > 0) {
 
-                    for (ic = 0; ic < r->i_ss.channels; ic++)
-                        if (on_left(r->i_cm.map[ic]) || on_right(r->i_cm.map[ic]))
-                            n++;
+                        /* Hmm, no center channel around, let's synthesize it
+                         * by mixing L and R.*/
 
-                    if (n > 0)
-                        for (ic = 0; ic < r->i_ss.channels; ic++)
+                        for (ic = 0; ic < n_ic; ic++)
                             if (on_left(r->i_cm.map[ic]) || on_right(r->i_cm.map[ic])) {
-                                r->map_table[oc][ic] = 1.0f / (float) n;
-                                ic_connected[ic] = TRUE;
+                                m->map_table_f[oc][ic] = 1.0f / (float) (ic_left + ic_right);
+                                ic_connected[ic] = true;
                             }
+                    }
 
-                    /* We ignore the case where there is not even a
-                     * left or right input channel. Something is
-                     * really wrong in this case anyway. */
-                }
-
-            } else if (on_lfe(b)) {
+                    /* We ignore the case where there is not even a left or
+                     * right input channel. Something is really wrong in this
+                     * case anyway. */
 
-                /* We are not connected and an LFE. Let's average all
-                 * channels for LFE. */
+                } else if (on_lfe(b) && !(r->flags & PA_RESAMPLER_NO_LFE)) {
 
-                for (ic = 0; ic < r->i_ss.channels; ic++) {
+                    /* We are not connected and an LFE. Let's average all
+                     * channels for LFE. */
 
-                    if (!(r->flags & PA_RESAMPLER_NO_LFE))
-                        r->map_table[oc][ic] = 1.0f / (float) r->i_ss.channels;
-                    else
-                        r->map_table[oc][ic] = 0;
+                    for (ic = 0; ic < n_ic; ic++)
+                        m->map_table_f[oc][ic] = 1.0f / (float) n_ic;
 
-                    /* Please note that a channel connected to LFE
-                     * doesn't really count as connected. */
+                    /* Please note that a channel connected to LFE doesn't
+                     * really count as connected. */
                 }
             }
         }
-    }
-
-    if (remix) {
-        unsigned
-            ic_unconnected_left = 0,
-            ic_unconnected_right = 0,
-            ic_unconnected_center = 0,
-            ic_unconnected_lfe = 0;
 
-        for (ic = 0; ic < r->i_ss.channels; ic++) {
+        for (ic = 0; ic < n_ic; ic++) {
             pa_channel_position_t a = r->i_cm.map[ic];
 
             if (ic_connected[ic])
@@ -752,148 +887,130 @@ static void calc_map_table(pa_resampler *r) {
                 ic_unconnected_lfe++;
         }
 
-        if (ic_unconnected_left > 0) {
+        for (ic = 0; ic < n_ic; ic++) {
+            pa_channel_position_t a = r->i_cm.map[ic];
 
-            /* OK, so there are unconnected input channels on the
-             * left. Let's multiply all already connected channels on
-             * the left side by .9 and add in our averaged unconnected
-             * channels multplied by .1 */
+            if (ic_connected[ic])
+                continue;
 
-            for (oc = 0; oc < r->o_ss.channels; oc++) {
+            for (oc = 0; oc < n_oc; oc++) {
+                pa_channel_position_t b = r->o_cm.map[oc];
 
-                if (!on_left(r->o_cm.map[oc]))
-                    continue;
+                if (on_left(a) && on_left(b))
+                    m->map_table_f[oc][ic] = (1.f/9.f) / (float) ic_unconnected_left;
 
-                for (ic = 0; ic < r->i_ss.channels; ic++) {
+                else if (on_right(a) && on_right(b))
+                    m->map_table_f[oc][ic] = (1.f/9.f) / (float) ic_unconnected_right;
 
-                    if (ic_connected[ic]) {
-                        r->map_table[oc][ic] *= .9f;
-                        continue;
-                    }
+                else if (on_center(a) && on_center(b)) {
+                    m->map_table_f[oc][ic] = (1.f/9.f) / (float) ic_unconnected_center;
+                    ic_unconnected_center_mixed_in = true;
 
-                    if (on_left(r->i_cm.map[ic]))
-                        r->map_table[oc][ic] = .1f / (float) ic_unconnected_left;
-                }
+                } else if (on_lfe(a) && !(r->flags & PA_RESAMPLER_NO_LFE))
+                    m->map_table_f[oc][ic] = .375f / (float) ic_unconnected_lfe;
             }
         }
 
-        if (ic_unconnected_right > 0) {
+        if (ic_unconnected_center > 0 && !ic_unconnected_center_mixed_in) {
+            unsigned ncenter[PA_CHANNELS_MAX];
+            bool found_frs[PA_CHANNELS_MAX];
 
-            /* OK, so there are unconnected input channels on the
-             * right. Let's multiply all already connected channels on
-             * the right side by .9 and add in our averaged unconnected
-             * channels multplied by .1 */
+            memset(ncenter, 0, sizeof(ncenter));
+            memset(found_frs, 0, sizeof(found_frs));
 
-            for (oc = 0; oc < r->o_ss.channels; oc++) {
+            /* Hmm, as it appears there was no center channel we
+               could mix our center channel in. In this case, mix it into
+               left and right. Using .5 as the factor. */
 
-                if (!on_right(r->o_cm.map[oc]))
-                    continue;
+            for (ic = 0; ic < n_ic; ic++) {
 
-                for (ic = 0; ic < r->i_ss.channels; ic++) {
-
-                    if (ic_connected[ic]) {
-                        r->map_table[oc][ic] *= .9f;
-                        continue;
-                    }
-
-                    if (on_right(r->i_cm.map[ic]))
-                        r->map_table[oc][ic] = .1f / (float) ic_unconnected_right;
-                }
-            }
-        }
-
-        if (ic_unconnected_center > 0) {
-            pa_bool_t mixed_in = FALSE;
-
-            /* OK, so there are unconnected input channels on the
-             * center. Let's multiply all already connected channels on
-             * the center side by .9 and add in our averaged unconnected
-             * channels multplied by .1 */
-
-            for (oc = 0; oc < r->o_ss.channels; oc++) {
+                if (ic_connected[ic])
+                    continue;
 
-                if (!on_center(r->o_cm.map[oc]))
+                if (!on_center(r->i_cm.map[ic]))
                     continue;
 
-                for (ic = 0; ic < r->i_ss.channels; ic++)  {
+                for (oc = 0; oc < n_oc; oc++) {
 
-                    if (ic_connected[ic]) {
-                        r->map_table[oc][ic] *= .9f;
+                    if (!on_left(r->o_cm.map[oc]) && !on_right(r->o_cm.map[oc]))
                         continue;
-                    }
 
-                    if (on_center(r->i_cm.map[ic])) {
-                        r->map_table[oc][ic] = .1f / (float) ic_unconnected_center;
-                        mixed_in = TRUE;
+                    if (front_rear_side(r->i_cm.map[ic]) == front_rear_side(r->o_cm.map[oc])) {
+                        found_frs[ic] = true;
+                        break;
                     }
                 }
-            }
 
-            if (!mixed_in) {
-
-                /* Hmm, as it appears there was no center channel we
-                   could mix our center channel in. In this case, mix
-                   it into left and right. Using .375 and 0.75 as
-                   factors. */
-
-                for (oc = 0; oc < r->o_ss.channels; oc++) {
+                for (oc = 0; oc < n_oc; oc++) {
 
                     if (!on_left(r->o_cm.map[oc]) && !on_right(r->o_cm.map[oc]))
                         continue;
 
-                    for (ic = 0; ic < r->i_ss.channels; ic++)  {
-
-                        if (ic_connected[ic]) {
-                            r->map_table[oc][ic] *= .75f;
-                            continue;
-                        }
-
-                        if (on_center(r->i_cm.map[ic]))
-                            r->map_table[oc][ic] = .375f / (float) ic_unconnected_center;
-                    }
+                    if (!found_frs[ic] || front_rear_side(r->i_cm.map[ic]) == front_rear_side(r->o_cm.map[oc]))
+                        ncenter[oc]++;
                 }
             }
-        }
-
-        if (ic_unconnected_lfe > 0 && !(r->flags & PA_RESAMPLER_NO_LFE)) {
 
-            /* OK, so there is an unconnected LFE channel. Let's mix
-             * it into all channels, with factor 0.375 */
+            for (oc = 0; oc < n_oc; oc++) {
 
-            for (ic = 0; ic < r->i_ss.channels; ic++)  {
+                if (!on_left(r->o_cm.map[oc]) && !on_right(r->o_cm.map[oc]))
+                    continue;
 
-                if (!on_lfe(r->i_cm.map[ic]))
+                if (ncenter[oc] <= 0)
                     continue;
 
-                for (oc = 0; oc < r->o_ss.channels; oc++)
-                    r->map_table[oc][ic] = 0.375f / (float) ic_unconnected_lfe;
+                for (ic = 0; ic < n_ic; ic++) {
+
+                    if (!on_center(r->i_cm.map[ic]))
+                        continue;
+
+                    if (!found_frs[ic] || front_rear_side(r->i_cm.map[ic]) == front_rear_side(r->o_cm.map[oc]))
+                        m->map_table_f[oc][ic] = .5f / (float) ncenter[oc];
+                }
             }
         }
     }
 
+    for (oc = 0; oc < n_oc; oc++) {
+        float sum = 0.0f;
+        for (ic = 0; ic < n_ic; ic++)
+            sum += m->map_table_f[oc][ic];
+
+        if (sum > 1.0f)
+            for (ic = 0; ic < n_ic; ic++)
+                m->map_table_f[oc][ic] /= sum;
+    }
+
+    /* make an 16:16 int version of the matrix */
+    for (oc = 0; oc < n_oc; oc++)
+        for (ic = 0; ic < n_ic; ic++)
+            m->map_table_i[oc][ic] = (int32_t) (m->map_table_f[oc][ic] * 0x10000);
 
     s = pa_strbuf_new();
 
     pa_strbuf_printf(s, "     ");
-    for (ic = 0; ic < r->i_ss.channels; ic++)
+    for (ic = 0; ic < n_ic; ic++)
         pa_strbuf_printf(s, "  I%02u ", ic);
     pa_strbuf_puts(s, "\n    +");
 
-    for (ic = 0; ic < r->i_ss.channels; ic++)
+    for (ic = 0; ic < n_ic; ic++)
         pa_strbuf_printf(s, "------");
     pa_strbuf_puts(s, "\n");
 
-    for (oc = 0; oc < r->o_ss.channels; oc++) {
+    for (oc = 0; oc < n_oc; oc++) {
         pa_strbuf_printf(s, "O%02u |", oc);
 
-        for (ic = 0; ic < r->i_ss.channels; ic++)
-            pa_strbuf_printf(s, " %1.3f", r->map_table[oc][ic]);
+        for (ic = 0; ic < n_ic; ic++)
+            pa_strbuf_printf(s, " %1.3f", m->map_table_f[oc][ic]);
 
         pa_strbuf_puts(s, "\n");
     }
 
     pa_log_debug("Channel matrix:\n%s", t = pa_strbuf_tostring_free(s));
     pa_xfree(t);
+
+    /* initialize the remapping function */
+    pa_init_remap(m);
 }
 
 static pa_memchunk* convert_to_work_format(pa_resampler *r, pa_memchunk *input) {
@@ -904,169 +1021,110 @@ static pa_memchunk* convert_to_work_format(pa_resampler *r, pa_memchunk *input)
     pa_assert(input);
     pa_assert(input->memblock);
 
-    /* Convert the incoming sample into the work sample format and place them in buf1 */
+    /* Convert the incoming sample into the work sample format and place them
+     * in to_work_format_buf. */
 
     if (!r->to_work_format_func || !input->length)
         return input;
 
     n_samples = (unsigned) ((input->length / r->i_fz) * r->i_ss.channels);
 
-    r->buf1.index = 0;
-    r->buf1.length = r->w_sz * n_samples;
+    r->to_work_format_buf.index = 0;
+    r->to_work_format_buf.length = r->w_sz * n_samples;
 
-    if (!r->buf1.memblock || r->buf1_samples < n_samples) {
-        if (r->buf1.memblock)
-            pa_memblock_unref(r->buf1.memblock);
+    if (!r->to_work_format_buf.memblock || r->to_work_format_buf_samples < n_samples) {
+        if (r->to_work_format_buf.memblock)
+            pa_memblock_unref(r->to_work_format_buf.memblock);
 
-        r->buf1_samples = n_samples;
-        r->buf1.memblock = pa_memblock_new(r->mempool, r->buf1.length);
+        r->to_work_format_buf_samples = n_samples;
+        r->to_work_format_buf.memblock = pa_memblock_new(r->mempool, r->to_work_format_buf.length);
     }
 
-    src = (uint8_t*) pa_memblock_acquire(input->memblock) + input->index;
-    dst = (uint8_t*) pa_memblock_acquire(r->buf1.memblock);
+    src = pa_memblock_acquire_chunk(input);
+    dst = pa_memblock_acquire(r->to_work_format_buf.memblock);
 
     r->to_work_format_func(n_samples, src, dst);
 
     pa_memblock_release(input->memblock);
-    pa_memblock_release(r->buf1.memblock);
+    pa_memblock_release(r->to_work_format_buf.memblock);
 
-    return &r->buf1;
-}
-
-static void vectoradd_s16_with_fraction(
-        int16_t *d, int dstr,
-        const int16_t *s1, int sstr1,
-        const int16_t *s2, int sstr2,
-        int n,
-        float s3, float s4) {
-
-    int32_t i3, i4;
-
-    i3 = (int32_t) (s3 * 0x10000);
-    i4 = (int32_t) (s4 * 0x10000);
-
-    for (; n > 0; n--) {
-        int32_t a, b;
-
-        a = *s1;
-        b = *s2;
-
-        a = (a * i3) / 0x10000;
-        b = (b * i4) / 0x10000;
-
-        *d = (int16_t) (a + b);
-
-        s1 = (const int16_t*) ((const uint8_t*) s1 + sstr1);
-        s2 = (const int16_t*) ((const uint8_t*) s2 + sstr2);
-        d = (int16_t*) ((uint8_t*) d + dstr);
-
-    }
+    return &r->to_work_format_buf;
 }
 
 static pa_memchunk *remap_channels(pa_resampler *r, pa_memchunk *input) {
-    unsigned in_n_samples, out_n_samples, n_frames;
-    int i_skip, o_skip;
-    unsigned oc;
+    unsigned in_n_samples, out_n_samples, in_n_frames, out_n_frames;
     void *src, *dst;
+    size_t leftover_length = 0;
+    bool have_leftover;
 
     pa_assert(r);
     pa_assert(input);
     pa_assert(input->memblock);
 
-    /* Remap channels and place the result int buf2 */
+    /* Remap channels and place the result in remap_buf. There may be leftover
+     * data in the beginning of remap_buf. The leftover data is already
+     * remapped, so it's not part of the input, it's part of the output. */
+
+    have_leftover = r->remap_buf_contains_leftover_data;
+    r->remap_buf_contains_leftover_data = false;
 
-    if (!r->map_required || !input->length)
+    if (!have_leftover && (!r->map_required || input->length <= 0))
         return input;
+    else if (input->length <= 0)
+        return &r->remap_buf;
 
     in_n_samples = (unsigned) (input->length / r->w_sz);
-    n_frames = in_n_samples / r->i_ss.channels;
-    out_n_samples = n_frames * r->o_ss.channels;
-
-    r->buf2.index = 0;
-    r->buf2.length = r->w_sz * out_n_samples;
+    in_n_frames = out_n_frames = in_n_samples / r->i_ss.channels;
 
-    if (!r->buf2.memblock || r->buf2_samples < out_n_samples) {
-        if (r->buf2.memblock)
-            pa_memblock_unref(r->buf2.memblock);
-
-        r->buf2_samples = out_n_samples;
-        r->buf2.memblock = pa_memblock_new(r->mempool, r->buf2.length);
+    if (have_leftover) {
+        leftover_length = r->remap_buf.length;
+        out_n_frames += leftover_length / (r->w_sz * r->o_ss.channels);
     }
 
-    src = ((uint8_t*) pa_memblock_acquire(input->memblock) + input->index);
-    dst = pa_memblock_acquire(r->buf2.memblock);
-
-    memset(dst, 0, r->buf2.length);
-
-    o_skip = (int) (r->w_sz * r->o_ss.channels);
-    i_skip = (int) (r->w_sz * r->i_ss.channels);
-
-    switch (r->work_format) {
-        case PA_SAMPLE_FLOAT32NE:
-
-            for (oc = 0; oc < r->o_ss.channels; oc++) {
-                unsigned ic;
-                static const float one = 1.0;
-
-                for (ic = 0; ic < r->i_ss.channels; ic++) {
-
-                    if (r->map_table[oc][ic] <= 0.0)
-                        continue;
-
-                    oil_vectoradd_f32(
-                            (float*) dst + oc, o_skip,
-                            (float*) dst + oc, o_skip,
-                            (float*) src + ic, i_skip,
-                            (int) n_frames,
-                            &one, &r->map_table[oc][ic]);
-                }
-            }
-
-            break;
+    out_n_samples = out_n_frames * r->o_ss.channels;
+    r->remap_buf.length = out_n_samples * r->w_sz;
 
-        case PA_SAMPLE_S16NE:
+    if (have_leftover) {
+        if (r->remap_buf_size < r->remap_buf.length) {
+            pa_memblock *new_block = pa_memblock_new(r->mempool, r->remap_buf.length);
 
-            for (oc = 0; oc < r->o_ss.channels; oc++) {
-                unsigned ic;
+            src = pa_memblock_acquire(r->remap_buf.memblock);
+            dst = pa_memblock_acquire(new_block);
+            memcpy(dst, src, leftover_length);
+            pa_memblock_release(r->remap_buf.memblock);
+            pa_memblock_release(new_block);
 
-                for (ic = 0; ic < r->i_ss.channels; ic++) {
+            pa_memblock_unref(r->remap_buf.memblock);
+            r->remap_buf.memblock = new_block;
+            r->remap_buf_size = r->remap_buf.length;
+        }
 
-                    if (r->map_table[oc][ic] <= 0.0)
-                        continue;
+    } else {
+        if (!r->remap_buf.memblock || r->remap_buf_size < r->remap_buf.length) {
+            if (r->remap_buf.memblock)
+                pa_memblock_unref(r->remap_buf.memblock);
 
-                    if (r->map_table[oc][ic] >= 1.0) {
-                        static const int16_t one = 1;
+            r->remap_buf_size = r->remap_buf.length;
+            r->remap_buf.memblock = pa_memblock_new(r->mempool, r->remap_buf.length);
+        }
+    }
 
-                        oil_vectoradd_s16(
-                                (int16_t*) dst + oc, o_skip,
-                                (int16_t*) dst + oc, o_skip,
-                                (int16_t*) src + ic, i_skip,
-                                (int) n_frames,
-                                &one, &one);
+    src = pa_memblock_acquire_chunk(input);
+    dst = (uint8_t *) pa_memblock_acquire(r->remap_buf.memblock) + leftover_length;
 
-                    } else
+    if (r->map_required) {
+        pa_remap_t *remap = &r->remap;
 
-                        vectoradd_s16_with_fraction(
-                                (int16_t*) dst + oc, o_skip,
-                                (int16_t*) dst + oc, o_skip,
-                                (int16_t*) src + ic, i_skip,
-                                (int) n_frames,
-                                1.0f, r->map_table[oc][ic]);
-                }
-            }
+        pa_assert(remap->do_remap);
+        remap->do_remap(remap, dst, src, in_n_frames);
 
-            break;
-
-        default:
-            pa_assert_not_reached();
-    }
+    } else
+        memcpy(dst, src, input->length);
 
     pa_memblock_release(input->memblock);
-    pa_memblock_release(r->buf2.memblock);
-
-    r->buf2.length = out_n_samples * r->w_sz;
+    pa_memblock_release(r->remap_buf.memblock);
 
-    return &r->buf2;
+    return &r->remap_buf;
 }
 
 static pa_memchunk *resample(pa_resampler *r, pa_memchunk *input) {
@@ -1076,7 +1134,7 @@ static pa_memchunk *resample(pa_resampler *r, pa_memchunk *input) {
     pa_assert(r);
     pa_assert(input);
 
-    /* Resample the data and place the result in buf3 */
+    /* Resample the data and place the result in resample_buf. */
 
     if (!r->impl_resample || !input->length)
         return input;
@@ -1087,21 +1145,21 @@ static pa_memchunk *resample(pa_resampler *r, pa_memchunk *input) {
     out_n_frames = ((in_n_frames*r->o_ss.rate)/r->i_ss.rate)+EXTRA_FRAMES;
     out_n_samples = out_n_frames * r->o_ss.channels;
 
-    r->buf3.index = 0;
-    r->buf3.length = r->w_sz * out_n_samples;
+    r->resample_buf.index = 0;
+    r->resample_buf.length = r->w_sz * out_n_samples;
 
-    if (!r->buf3.memblock || r->buf3_samples < out_n_samples) {
-        if (r->buf3.memblock)
-            pa_memblock_unref(r->buf3.memblock);
+    if (!r->resample_buf.memblock || r->resample_buf_samples < out_n_samples) {
+        if (r->resample_buf.memblock)
+            pa_memblock_unref(r->resample_buf.memblock);
 
-        r->buf3_samples = out_n_samples;
-        r->buf3.memblock = pa_memblock_new(r->mempool, r->buf3.length);
+        r->resample_buf_samples = out_n_samples;
+        r->resample_buf.memblock = pa_memblock_new(r->mempool, r->resample_buf.length);
     }
 
-    r->impl_resample(r, input, in_n_frames, &r->buf3, &out_n_frames);
-    r->buf3.length = out_n_frames * r->w_sz * r->o_ss.channels;
+    r->impl_resample(r, input, in_n_frames, &r->resample_buf, &out_n_frames);
+    r->resample_buf.length = out_n_frames * r->w_sz * r->o_ss.channels;
 
-    return &r->buf3;
+    return &r->resample_buf;
 }
 
 static pa_memchunk *convert_from_work_format(pa_resampler *r, pa_memchunk *input) {
@@ -1111,7 +1169,8 @@ static pa_memchunk *convert_from_work_format(pa_resampler *r, pa_memchunk *input
     pa_assert(r);
     pa_assert(input);
 
-    /* Convert the data into the correct sample type and place the result in buf4 */
+    /* Convert the data into the correct sample type and place the result in
+     * from_work_format_buf. */
 
     if (!r->from_work_format_func || !input->length)
         return input;
@@ -1119,26 +1178,24 @@ static pa_memchunk *convert_from_work_format(pa_resampler *r, pa_memchunk *input
     n_samples = (unsigned) (input->length / r->w_sz);
     n_frames = n_samples / r->o_ss.channels;
 
-    r->buf4.index = 0;
-    r->buf4.length = r->o_fz * n_frames;
+    r->from_work_format_buf.index = 0;
+    r->from_work_format_buf.length = r->o_fz * n_frames;
 
-    if (!r->buf4.memblock || r->buf4_samples < n_samples) {
-        if (r->buf4.memblock)
-            pa_memblock_unref(r->buf4.memblock);
+    if (!r->from_work_format_buf.memblock || r->from_work_format_buf_samples < n_samples) {
+        if (r->from_work_format_buf.memblock)
+            pa_memblock_unref(r->from_work_format_buf.memblock);
 
-        r->buf4_samples = n_samples;
-        r->buf4.memblock = pa_memblock_new(r->mempool, r->buf4.length);
+        r->from_work_format_buf_samples = n_samples;
+        r->from_work_format_buf.memblock = pa_memblock_new(r->mempool, r->from_work_format_buf.length);
     }
 
-    src = (uint8_t*) pa_memblock_acquire(input->memblock) + input->index;
-    dst = pa_memblock_acquire(r->buf4.memblock);
+    src = pa_memblock_acquire_chunk(input);
+    dst = pa_memblock_acquire(r->from_work_format_buf.memblock);
     r->from_work_format_func(n_samples, src, dst);
     pa_memblock_release(input->memblock);
-    pa_memblock_release(r->buf4.memblock);
+    pa_memblock_release(r->from_work_format_buf.memblock);
 
-    r->buf4.length = r->o_fz * n_frames;
-
-    return &r->buf4;
+    return &r->from_work_format_buf;
 }
 
 void pa_resampler_run(pa_resampler *r, const pa_memchunk *in, pa_memchunk *out) {
@@ -1168,6 +1225,32 @@ void pa_resampler_run(pa_resampler *r, const pa_memchunk *in, pa_memchunk *out)
         pa_memchunk_reset(out);
 }
 
+static void save_leftover(pa_resampler *r, void *buf, size_t len) {
+    void *dst;
+
+    pa_assert(r);
+    pa_assert(buf);
+    pa_assert(len > 0);
+
+    /* Store the leftover to remap_buf. */
+
+    r->remap_buf.length = len;
+
+    if (!r->remap_buf.memblock || r->remap_buf_size < r->remap_buf.length) {
+        if (r->remap_buf.memblock)
+            pa_memblock_unref(r->remap_buf.memblock);
+
+        r->remap_buf_size = r->remap_buf.length;
+        r->remap_buf.memblock = pa_memblock_new(r->mempool, r->remap_buf.length);
+    }
+
+    dst = pa_memblock_acquire(r->remap_buf.memblock);
+    memcpy(dst, buf, r->remap_buf.length);
+    pa_memblock_release(r->remap_buf.memblock);
+
+    r->remap_buf_contains_leftover_data = true;
+}
+
 /*** libsamplerate based implementation ***/
 
 #ifdef HAVE_LIBSAMPLERATE
@@ -1181,17 +1264,23 @@ static void libsamplerate_resample(pa_resampler *r, const pa_memchunk *input, un
 
     memset(&data, 0, sizeof(data));
 
-    data.data_in = (float*) ((uint8_t*) pa_memblock_acquire(input->memblock) + input->index);
+    data.data_in = pa_memblock_acquire_chunk(input);
     data.input_frames = (long int) in_n_frames;
 
-    data.data_out = (float*) ((uint8_t*) pa_memblock_acquire(output->memblock) + output->index);
+    data.data_out = pa_memblock_acquire_chunk(output);
     data.output_frames = (long int) *out_n_frames;
 
     data.src_ratio = (double) r->o_ss.rate / r->i_ss.rate;
     data.end_of_input = 0;
 
     pa_assert_se(src_process(r->src.state, &data) == 0);
-    pa_assert((unsigned) data.input_frames_used == in_n_frames);
+
+    if (data.input_frames_used < in_n_frames) {
+        void *leftover_data = data.data_in + data.input_frames_used * r->o_ss.channels;
+        size_t leftover_length = (in_n_frames - data.input_frames_used) * sizeof(float) * r->o_ss.channels;
+
+        save_leftover(r, leftover_data, leftover_length);
+    }
 
     pa_memblock_release(input->memblock);
     pa_memblock_release(output->memblock);
@@ -1235,6 +1324,7 @@ static int libsamplerate_init(pa_resampler *r) {
 }
 #endif
 
+#ifdef HAVE_SPEEX
 /*** speex based implementation ***/
 
 static void speex_resample_float(pa_resampler *r, const pa_memchunk *input, unsigned in_n_frames, pa_memchunk *output, unsigned *out_n_frames) {
@@ -1246,8 +1336,8 @@ static void speex_resample_float(pa_resampler *r, const pa_memchunk *input, unsi
     pa_assert(output);
     pa_assert(out_n_frames);
 
-    in = (float*) ((uint8_t*) pa_memblock_acquire(input->memblock) + input->index);
-    out = (float*) ((uint8_t*) pa_memblock_acquire(output->memblock) + output->index);
+    in = pa_memblock_acquire_chunk(input);
+    out = pa_memblock_acquire_chunk(output);
 
     pa_assert_se(speex_resampler_process_interleaved_float(r->speex.state, in, &inf, out, &outf) == 0);
 
@@ -1267,8 +1357,8 @@ static void speex_resample_int(pa_resampler *r, const pa_memchunk *input, unsign
     pa_assert(output);
     pa_assert(out_n_frames);
 
-    in = (int16_t*) ((uint8_t*) pa_memblock_acquire(input->memblock) + input->index);
-    out = (int16_t*) ((uint8_t*) pa_memblock_acquire(output->memblock) + output->index);
+    in = pa_memblock_acquire_chunk(input);
+    out = pa_memblock_acquire_chunk(output);
 
     pa_assert_se(speex_resampler_process_interleaved_int(r->speex.state, in, &inf, out, &outf) == 0);
 
@@ -1328,12 +1418,13 @@ static int speex_init(pa_resampler *r) {
 
     return 0;
 }
+#endif
 
 /* Trivial implementation */
 
 static void trivial_resample(pa_resampler *r, const pa_memchunk *input, unsigned in_n_frames, pa_memchunk *output, unsigned *out_n_frames) {
     size_t fz;
-    unsigned o_index;
+    unsigned i_index, o_index;
     void *src, *dst;
 
     pa_assert(r);
@@ -1343,22 +1434,19 @@ static void trivial_resample(pa_resampler *r, const pa_memchunk *input, unsigned
 
     fz = r->w_sz * r->o_ss.channels;
 
-    src = (uint8_t*) pa_memblock_acquire(input->memblock) + input->index;
-    dst = (uint8_t*) pa_memblock_acquire(output->memblock) + output->index;
+    src = pa_memblock_acquire_chunk(input);
+    dst = pa_memblock_acquire_chunk(output);
 
     for (o_index = 0;; o_index++, r->trivial.o_counter++) {
-        unsigned j;
+        i_index = ((uint64_t) r->trivial.o_counter * r->i_ss.rate) / r->o_ss.rate;
+        i_index = i_index > r->trivial.i_counter ? i_index - r->trivial.i_counter : 0;
 
-        j = ((r->trivial.o_counter * r->i_ss.rate) / r->o_ss.rate);
-        j = j > r->trivial.i_counter ? j - r->trivial.i_counter : 0;
-
-        if (j >= in_n_frames)
+        if (i_index >= in_n_frames)
             break;
 
-        pa_assert(o_index * fz < pa_memblock_get_length(output->memblock));
+        pa_assert_fp(o_index * fz < pa_memblock_get_length(output->memblock));
 
-        oil_memcpy((uint8_t*) dst + fz * o_index,
-                   (uint8_t*) src + fz * j, (int) fz);
+        memcpy((uint8_t*) dst + fz * o_index, (uint8_t*) src + fz * i_index, (int) fz);
     }
 
     pa_memblock_release(input->memblock);
@@ -1399,82 +1487,83 @@ static int trivial_init(pa_resampler*r) {
 /* Peak finder implementation */
 
 static void peaks_resample(pa_resampler *r, const pa_memchunk *input, unsigned in_n_frames, pa_memchunk *output, unsigned *out_n_frames) {
-    size_t fz;
-    unsigned o_index;
+    unsigned c, o_index = 0;
+    unsigned i, i_end = 0;
     void *src, *dst;
-    unsigned start = 0;
 
     pa_assert(r);
     pa_assert(input);
     pa_assert(output);
     pa_assert(out_n_frames);
 
-    fz = r->w_sz * r->o_ss.channels;
-
-    src = (uint8_t*) pa_memblock_acquire(input->memblock) + input->index;
-    dst = (uint8_t*) pa_memblock_acquire(output->memblock) + output->index;
+    src = pa_memblock_acquire_chunk(input);
+    dst = pa_memblock_acquire_chunk(output);
 
-    for (o_index = 0;; o_index++, r->peaks.o_counter++) {
-        unsigned j;
+    i = ((uint64_t) r->peaks.o_counter * r->i_ss.rate) / r->o_ss.rate;
+    i = i > r->peaks.i_counter ? i - r->peaks.i_counter : 0;
 
-        j = ((r->peaks.o_counter * r->i_ss.rate) / r->o_ss.rate);
+    while (i_end < in_n_frames) {
+        i_end = ((uint64_t) (r->peaks.o_counter + 1) * r->i_ss.rate) / r->o_ss.rate;
+        i_end = i_end > r->peaks.i_counter ? i_end - r->peaks.i_counter : 0;
 
-        if (j > r->peaks.i_counter)
-            j -= r->peaks.i_counter;
-        else
-            j = 0;
+        pa_assert_fp(o_index * r->w_sz * r->o_ss.channels < pa_memblock_get_length(output->memblock));
 
-        pa_assert(o_index * fz < pa_memblock_get_length(output->memblock));
+        /* 1ch float is treated separately, because that is the common case */
+        if (r->o_ss.channels == 1 && r->work_format == PA_SAMPLE_FLOAT32NE) {
+            float *s = (float*) src + i;
+            float *d = (float*) dst + o_index;
 
-        if (r->work_format == PA_SAMPLE_S16NE) {
-            unsigned i, c;
-            int16_t *s = (int16_t*) ((uint8_t*) src + fz * start);
-            int16_t *d = (int16_t*) ((uint8_t*) dst + fz * o_index);
+            for (; i < i_end && i < in_n_frames; i++) {
+                float n = fabsf(*s++);
 
-            for (i = start; i <= j && i < in_n_frames; i++)
+                if (n > r->peaks.max_f[0])
+                    r->peaks.max_f[0] = n;
+            }
 
-                for (c = 0; c < r->o_ss.channels; c++, s++) {
-                    int16_t n;
+            if (i == i_end) {
+                *d = r->peaks.max_f[0];
+                r->peaks.max_f[0] = 0;
+                o_index++, r->peaks.o_counter++;
+            }
+        } else if (r->work_format == PA_SAMPLE_S16NE) {
+            int16_t *s = (int16_t*) src + r->i_ss.channels * i;
+            int16_t *d = (int16_t*) dst + r->o_ss.channels * o_index;
 
-                    n = (int16_t) (*s < 0 ? -*s : *s);
+            for (; i < i_end && i < in_n_frames; i++)
+                for (c = 0; c < r->o_ss.channels; c++) {
+                    int16_t n = abs(*s++);
 
-                    if (PA_UNLIKELY(n > r->peaks.max_i[c]))
+                    if (n > r->peaks.max_i[c])
                         r->peaks.max_i[c] = n;
                 }
 
-            if (i >= in_n_frames)
-                break;
-
-            for (c = 0; c < r->o_ss.channels; c++, d++) {
-                *d = r->peaks.max_i[c];
-                r->peaks.max_i[c] = 0;
+            if (i == i_end) {
+                for (c = 0; c < r->o_ss.channels; c++, d++) {
+                    *d = r->peaks.max_i[c];
+                    r->peaks.max_i[c] = 0;
+                }
+                o_index++, r->peaks.o_counter++;
             }
-
         } else {
-            unsigned i, c;
-            float *s = (float*) ((uint8_t*) src + fz * start);
-            float *d = (float*) ((uint8_t*) dst + fz * o_index);
-
-            pa_assert(r->work_format == PA_SAMPLE_FLOAT32NE);
+            float *s = (float*) src + r->i_ss.channels * i;
+            float *d = (float*) dst + r->o_ss.channels * o_index;
 
-            for (i = start; i <= j && i < in_n_frames; i++)
-                for (c = 0; c < r->o_ss.channels; c++, s++) {
-                    float n = fabsf(*s);
+            for (; i < i_end && i < in_n_frames; i++)
+                for (c = 0; c < r->o_ss.channels; c++) {
+                    float n = fabsf(*s++);
 
                     if (n > r->peaks.max_f[c])
                         r->peaks.max_f[c] = n;
                 }
 
-            if (i >= in_n_frames)
-                break;
-
-            for (c = 0; c < r->o_ss.channels; c++, d++) {
-                *d = r->peaks.max_f[c];
-                r->peaks.max_f[c] = 0;
+            if (i == i_end) {
+                for (c = 0; c < r->o_ss.channels; c++, d++) {
+                    *d = r->peaks.max_f[c];
+                    r->peaks.max_f[c] = 0;
+                }
+                o_index++, r->peaks.o_counter++;
             }
         }
-
-        start = j;
     }
 
     pa_memblock_release(input->memblock);
@@ -1502,6 +1591,8 @@ static void peaks_update_rates_or_reset(pa_resampler *r) {
 
 static int peaks_init(pa_resampler*r) {
     pa_assert(r);
+    pa_assert(r->i_ss.rate >= r->o_ss.rate);
+    pa_assert(r->work_format == PA_SAMPLE_S16NE || r->work_format == PA_SAMPLE_FLOAT32NE);
 
     r->peaks.o_counter = r->peaks.i_counter = 0;
     memset(r->peaks.max_i, 0, sizeof(r->peaks.max_i));
@@ -1518,6 +1609,7 @@ static int peaks_init(pa_resampler*r) {
 
 static void ffmpeg_resample(pa_resampler *r, const pa_memchunk *input, unsigned in_n_frames, pa_memchunk *output, unsigned *out_n_frames) {
     unsigned used_frames = 0, c;
+    int previous_consumed_frames = -1;
 
     pa_assert(r);
     pa_assert(input);
@@ -1529,25 +1621,14 @@ static void ffmpeg_resample(pa_resampler *r, const pa_memchunk *input, unsigned
         pa_memblock *b, *w;
         int16_t *p, *t, *k, *q, *s;
         int consumed_frames;
-        unsigned in, l;
 
         /* Allocate a new block */
         b = pa_memblock_new(r->mempool, r->ffmpeg.buf[c].length + in_n_frames * sizeof(int16_t));
         p = pa_memblock_acquire(b);
 
-        /* Copy the remaining data into it */
-        l = (unsigned) r->ffmpeg.buf[c].length;
-        if (r->ffmpeg.buf[c].memblock) {
-            t = (int16_t*) ((uint8_t*) pa_memblock_acquire(r->ffmpeg.buf[c].memblock) + r->ffmpeg.buf[c].index);
-            memcpy(p, t, l);
-            pa_memblock_release(r->ffmpeg.buf[c].memblock);
-            pa_memblock_unref(r->ffmpeg.buf[c].memblock);
-            pa_memchunk_reset(&r->ffmpeg.buf[c]);
-        }
-
-        /* Now append the new data, splitting up channels */
-        t = ((int16_t*) ((uint8_t*) pa_memblock_acquire(input->memblock) + input->index)) + c;
-        k = (int16_t*) ((uint8_t*) p + l);
+        /* Now copy the input data, splitting up channels */
+        t = (int16_t*) pa_memblock_acquire_chunk(input) + c;
+        k = p;
         for (u = 0; u < in_n_frames; u++) {
             *k = *t;
             t += r->o_ss.channels;
@@ -1555,9 +1636,6 @@ static void ffmpeg_resample(pa_resampler *r, const pa_memchunk *input, unsigned
         }
         pa_memblock_release(input->memblock);
 
-        /* Calculate the resulting number of frames */
-        in = (unsigned) in_n_frames + l / (unsigned) sizeof(int16_t);
-
         /* Allocate buffer for the result */
         w = pa_memblock_new(r->mempool, *out_n_frames * sizeof(int16_t));
         q = pa_memblock_acquire(w);
@@ -1566,22 +1644,18 @@ static void ffmpeg_resample(pa_resampler *r, const pa_memchunk *input, unsigned
         used_frames = (unsigned) av_resample(r->ffmpeg.state,
                                              q, p,
                                              &consumed_frames,
-                                             (int) in, (int) *out_n_frames,
+                                             (int) in_n_frames, (int) *out_n_frames,
                                              c >= (unsigned) (r->o_ss.channels-1));
 
         pa_memblock_release(b);
+        pa_memblock_unref(b);
 
-        /* Now store the remaining samples away */
-        pa_assert(consumed_frames <= (int) in);
-        if (consumed_frames < (int) in) {
-            r->ffmpeg.buf[c].memblock = b;
-            r->ffmpeg.buf[c].index = (size_t) consumed_frames * sizeof(int16_t);
-            r->ffmpeg.buf[c].length = (size_t) (in - (unsigned) consumed_frames) * sizeof(int16_t);
-        } else
-            pa_memblock_unref(b);
+        pa_assert(consumed_frames <= (int) in_n_frames);
+        pa_assert(previous_consumed_frames == -1 || consumed_frames == previous_consumed_frames);
+        previous_consumed_frames = consumed_frames;
 
         /* And place the results in the output buffer */
-        s = (short*) ((uint8_t*) pa_memblock_acquire(output->memblock) + output->index) + c;
+        s = (int16_t *) pa_memblock_acquire_chunk(output) + c;
         for (u = 0; u < used_frames; u++) {
             *s = *q;
             q++;
@@ -1592,6 +1666,14 @@ static void ffmpeg_resample(pa_resampler *r, const pa_memchunk *input, unsigned
         pa_memblock_unref(w);
     }
 
+    if (previous_consumed_frames < (int) in_n_frames) {
+        void *leftover_data = (int16_t *) pa_memblock_acquire_chunk(input) + previous_consumed_frames * r->o_ss.channels;
+        size_t leftover_length = (in_n_frames - previous_consumed_frames) * r->o_ss.channels * sizeof(int16_t);
+
+        save_leftover(r, leftover_data, leftover_length);
+        pa_memblock_release(input->memblock);
+    }
+
     *out_n_frames = used_frames;
 }