[vlc-commits] aout: do not check for PTS discontinuity in packetizer

[Rémi Denis-Courmont]

vlc | branch: master | Rémi Denis-Courmont <remi at remlab.net> | Thu Aug 11 23:19:07 2011 +0300| [0d087b3c4fafa7b5335b5fe4e24fc471312173bf] | committer: Rémi Denis-Courmont

aout: do not check for PTS discontinuity in packetizer

Continuity of the two FIFOs is maintained, as is consistency with the
input date. PTS discontinuity only seems to occur due to rounding
errors in the filters. It should be better not to drop samples, but
simply fix the buffer PTS and length.

Ideally, resamplers would use date_Increment() so they do not introduce
rounding errors. But first the block disconuity flag should be checked
for correctness during filtering, so that resamplers can reset the date
in case of hole.

> http://git.videolan.org/gitweb.cgi/vlc.git/?a=commit;h=0d087b3c4fafa7b5335b5fe4e24fc471312173bf
---

 src/audio_output/output.c |   62 +++------------------------------------------
 1 files changed, 4 insertions(+), 58 deletions(-)

diff --git a/src/audio_output/output.c b/src/audio_output/output.c
index 65a641a..4a268ae 100644
--- a/src/audio_output/output.c
+++ b/src/audio_output/output.c
@@ -485,76 +485,22 @@ static block_t *aout_OutputSlice (audio_output_t *p_aout)
     /* Compute the end date for the new buffer. */
     mtime_t end_date = date_Increment( &exact_start_date, samples );
 
-    /* Check that start_date is available. */
-    mtime_t prev_date;
-    for( ;; )
-    {
-        /* Check for the continuity of start_date */
-        prev_date = p_buffer->i_pts + p_buffer->i_length;
-        if( prev_date >= start_date - 1 )
-            break;
-        /* We authorize a +-1 because rounding errors get compensated
-         * regularly. */
-        msg_Warn( p_aout, "got a packet in the past (%"PRId64")",
-                  start_date - prev_date );
-        aout_BufferFree( aout_FifoPop( p_fifo ) );
-
-        p_buffer = p_fifo->p_first;
-        if( p_buffer == NULL )
-            return NULL;
-    }
-
-    /* Check that we have enough samples. */
-    while( prev_date < end_date )
+    /* Check that we have enough samples (TODO merge with next loop). */
+    for( unsigned available = 0; available < samples; )
     {
         p_buffer = p_buffer->p_next;
         if( p_buffer == NULL )
             return NULL;
 
-        /* Check that all buffers are contiguous. */
-        if( prev_date != p_buffer->i_pts )
-        {
-            msg_Warn( p_aout,
-                      "buffer hole, dropping packets (%"PRId64")",
-                      p_buffer->i_pts - prev_date );
-
-            aout_buffer_t *p_deleted;
-            while( (p_deleted = p_fifo->p_first) != p_buffer )
-                aout_BufferFree( aout_FifoPop( p_fifo ) );
-        }
-
-        prev_date = p_buffer->i_pts + p_buffer->i_length;
+        available += p_buffer->i_nb_samples;
     }
 
     if( AOUT_FMT_LINEAR( &p_aout->format ) )
     {
-        p_buffer = p_fifo->p_first;
-
-        /* Additionally check that p_first_byte_to_mix is well located. */
         const unsigned framesize = p_aout->format.i_bytes_per_frame;
-        ssize_t delta = (start_date - p_buffer->i_pts)
-                      * p_aout->format.i_rate / CLOCK_FREQ;
-        if( delta != 0 )
-            msg_Warn( p_aout, "input start is not output end (%zd)", delta );
-        if( delta < 0 )
-        {
-            /* Is it really the best way to do it ? */
-            aout_FifoReset (&p->fifo);
-            return NULL;
-        }
-        if( delta > 0 )
-        {
-            mtime_t t = delta * CLOCK_FREQ / p_aout->format.i_rate;
-            p_buffer->i_nb_samples -= delta;
-            p_buffer->i_pts += t;
-            p_buffer->i_length -= t;
-            delta *= framesize;
-            p_buffer->p_buffer += delta;
-            p_buffer->i_buffer -= delta;
-        }
-
         /* Build packet with adequate number of samples */
         unsigned needed = samples * framesize;
+
         p_buffer = block_Alloc( needed );
         if( unlikely(p_buffer == NULL) )
             /* XXX: should free input buffers */