demux_audio.c: Fix timestamp handling

The code calculated the pts values of audio packets by adding the length
of the current packet to the pts of the previous one. The length of the
previous packet should be added instead. This broke WAV timestamps near
the end of the stream where a short packet occurs.

Change the code to store the pts of the next packet instead of the last
one. This fixes the WAV timestamps and allows some simplifications.
MP3 timestamps are not affected as packets are always treated as
constant decoded length, and FLAC timestamps still have worse problems
(FLAC is treated as as if it was constant bitrate even though it isn't).

Also store the timestamps as double instead of float.


git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@24609 b3059339-0415-0410-9bf9-f77b7e298cf2

1 files changed, 15 insertions, 14 deletions

diff --git a/libmpdemux/demux_audio.c b/libmpdemux/demux_audio.c
index 0bdfd9343f..421a2702d6 100644
--- a/libmpdemux/demux_audio.c
+++ b/libmpdemux/demux_audio.c
@@ -26,7 +26,7 @@
 
 typedef struct da_priv {
   int frmt;
-  float last_pts;
+  double next_pts;
 } da_priv_t;
 
 //! rather arbitrary value for maximum length of wav-format headers
@@ -521,7 +521,7 @@ static int demux_audio_open(demuxer_t* demuxer) {
 
   priv = malloc(sizeof(da_priv_t));
   priv->frmt = frmt;
-  priv->last_pts = -1;
+  priv->next_pts = 0;
   demuxer->priv = priv;
   demuxer->audio->id = 0;
   demuxer->audio->sh = sh_audio;
@@ -570,6 +570,8 @@ static int demux_audio_fill_buffer(demuxer_t *demuxer, demux_stream_t *ds) {
   if(s->eof)
     return 0;
 
+  double this_pts = priv->next_pts;
+
   switch(priv->frmt) {
   case MP3 :
     while(1) {
@@ -590,7 +592,7 @@ static int demux_audio_fill_buffer(demuxer_t *demuxer, demux_stream_t *ds) {
 	  free_demux_packet(dp);
 	  return 0;
 	}
-	priv->last_pts = priv->last_pts < 0 ? 0 : priv->last_pts + sh_audio->audio.dwScale/(float)sh_audio->samplerate;
+	priv->next_pts += sh_audio->audio.dwScale/(double)sh_audio->samplerate;
 	break;
       }
     } break;
@@ -606,14 +608,15 @@ static int demux_audio_fill_buffer(demuxer_t *demuxer, demux_stream_t *ds) {
       l = (l + align - 1) / align * align;
     dp = new_demux_packet(l);
     l = stream_read(s,dp->buffer,l);
-    priv->last_pts = priv->last_pts < 0 ? 0 : priv->last_pts + l/(float)sh_audio->i_bps;
+    priv->next_pts += l/(double)sh_audio->i_bps;
     break;
   }
   case fLaC: {
     l = 65535;
     dp = new_demux_packet(l);
     l = stream_read(s,dp->buffer,l);
-    priv->last_pts = priv->last_pts < 0 ? 0 : priv->last_pts + l/(float)sh_audio->i_bps;
+    /* FLAC is not a constant-bitrate codec. These values will be wrong. */
+    priv->next_pts += l/(double)sh_audio->i_bps;
     break;
   }
   default:
@@ -622,7 +625,7 @@ static int demux_audio_fill_buffer(demuxer_t *demuxer, demux_stream_t *ds) {
   }
 
   resize_demux_packet(dp, l);
-  dp->pts = priv->last_pts;
+  dp->pts = this_pts;
   ds_add_packet(ds, dp);
   return 1;
 }
@@ -642,7 +645,7 @@ static void high_res_mp3_seek(demuxer_t *demuxer,float time) {
       continue;
     }
     stream_skip(demuxer->stream,len-4);
-    priv->last_pts += sh->audio.dwScale/(float)sh->samplerate;
+    priv->next_pts += sh->audio.dwScale/(double)sh->samplerate;
     nf--;
   }
 }
@@ -660,11 +663,11 @@ static void demux_audio_seek(demuxer_t *demuxer,float rel_seek_secs,float audio_
   priv = demuxer->priv;
 
   if(priv->frmt == MP3 && hr_mp3_seek && !(flags & 2)) {
-    len = (flags & 1) ? rel_seek_secs - priv->last_pts : rel_seek_secs;
+    len = (flags & 1) ? rel_seek_secs - priv->next_pts : rel_seek_secs;
     if(len < 0) {
       stream_seek(s,demuxer->movi_start);
-      len = priv->last_pts + len;
-      priv->last_pts = 0;
+      len = priv->next_pts + len;
+      priv->next_pts = 0;
     }
     if(len > 0)
       high_res_mp3_seek(demuxer,len);
@@ -682,15 +685,13 @@ static void demux_audio_seek(demuxer_t *demuxer,float rel_seek_secs,float audio_
   } else if(pos < demuxer->movi_start)
     pos = demuxer->movi_start;
 
-  priv->last_pts = (pos-demuxer->movi_start)/(float)sh_audio->i_bps;
+  priv->next_pts = (pos-demuxer->movi_start)/(double)sh_audio->i_bps;
   
   switch(priv->frmt) {
   case WAV:
     pos -= (pos - demuxer->movi_start) %
             (sh_audio->wf->nBlockAlign ? sh_audio->wf->nBlockAlign :
              (sh_audio->channels * sh_audio->samplesize));
-    // We need to decrease the pts by one step to make it the "last one"
-    priv->last_pts -= sh_audio->wf->nAvgBytesPerSec/(float)sh_audio->i_bps;
     break;
   }
 
@@ -719,7 +720,7 @@ static int demux_audio_control(demuxer_t *demuxer,int cmd, void *arg){
 	case DEMUXER_CTRL_GET_PERCENT_POS:
 	    if (audio_length<=0) 
     		return DEMUXER_CTRL_DONTKNOW;
-    	    *((int *)arg)=(int)( (priv->last_pts*100)  / audio_length);
+    	    *((int *)arg)=(int)( (priv->next_pts*100)  / audio_length);
 	    return DEMUXER_CTRL_OK;
 
 	default: