A rewind may erase data that sink_input counted in playing_for or
underrun_for earlier. Add code adjusting those values after a rewind.
One visible symptom of this bug was problems recovering from an
underrun. When a client calls pa_stream_write() with a large block of
memory, the function can split that into smaller pieces before sending
it to the server. When receiving new data for a stream that had
silence queued due to underrun, the server would do a rewind to
replace the queued-but-not-played silence with the new data. Because
of the bug, this rewind itself would not change underrun_for. It's
possible for multiple rewinds to be done without filling the sink
buffer in between (which is what would eventually reset underrun_for).
In this case, the server rapidly processing the split packets would
rewind the stream for _each_ of them (as underrun_for would stay set),
erasing valid audio as a result.
pa_memblockq_drop(i->thread_info.render_memblockq, nbytes);
}
pa_memblockq_drop(i->thread_info.render_memblockq, nbytes);
}
+static void subtract_helper(size_t *p, size_t amount)
+{
+ if (*p == (size_t) -1)
+ return;
+ if (*p < amount)
+ *p = 0;
+ *p -= amount;
+}
+
/* Called from thread context */
void pa_sink_input_process_rewind(pa_sink_input *i, size_t nbytes /* in sink sample spec */) {
size_t lbq;
/* Called from thread context */
void pa_sink_input_process_rewind(pa_sink_input *i, size_t nbytes /* in sink sample spec */) {
size_t lbq;
/* We were asked to drop all buffered data, and rerequest new
* data from implementor the next time peek() is called */
/* We were asked to drop all buffered data, and rerequest new
* data from implementor the next time peek() is called */
+ size_t s = pa_memblockq_get_length(i->thread_info.render_memblockq);
+ if (i->thread_info.resampler)
+ s = pa_resampler_request(i->thread_info.resampler, s);
pa_memblockq_flush_write(i->thread_info.render_memblockq, TRUE);
pa_memblockq_flush_write(i->thread_info.render_memblockq, TRUE);
+ subtract_helper(&i->thread_info.underrun_for, s);
+ subtract_helper(&i->thread_info.playing_for, s);
} else if (i->thread_info.rewrite_nbytes > 0) {
size_t max_rewrite, amount;
} else if (i->thread_info.rewrite_nbytes > 0) {
size_t max_rewrite, amount;
amount = PA_MIN(i->thread_info.rewrite_nbytes, max_rewrite);
if (amount > 0) {
amount = PA_MIN(i->thread_info.rewrite_nbytes, max_rewrite);
if (amount > 0) {
+ size_t samount = amount;
+
pa_log_debug("Have to rewind %lu bytes on implementor.", (unsigned long) amount);
/* Tell the implementor */
pa_log_debug("Have to rewind %lu bytes on implementor.", (unsigned long) amount);
/* Tell the implementor */
/* Convert back to to sink domain */
if (i->thread_info.resampler)
/* Convert back to to sink domain */
if (i->thread_info.resampler)
- amount = pa_resampler_result(i->thread_info.resampler, amount);
+ samount = pa_resampler_result(i->thread_info.resampler, amount);
/* Ok, now update the write pointer */
/* Ok, now update the write pointer */
- pa_memblockq_seek(i->thread_info.render_memblockq, - ((int64_t) amount), PA_SEEK_RELATIVE, TRUE);
+ pa_memblockq_seek(i->thread_info.render_memblockq, - ((int64_t) samount), PA_SEEK_RELATIVE, TRUE);
+ subtract_helper(&i->thread_info.underrun_for, amount);
+ subtract_helper(&i->thread_info.playing_for, amount);
+ }
if (i->thread_info.rewrite_flush)
pa_memblockq_silence(i->thread_info.render_memblockq);
if (i->thread_info.rewrite_flush)
pa_memblockq_silence(i->thread_info.render_memblockq);