avformat/dv: fix timestamps of audio packets in case of dropped corrupt audio frames

By using the frame counter (and the video time base) for audio pts we lose some
timestamp precision but we ensure that video and audio coming from the same DV
frame are always in sync.

This patch also makes timestamps after seek consistent and it should also fix
the timestamps when the audio clock is unlocked and have a completely
indpendent clock source. (E.g. runs on fixed 48009 Hz which should have been
exact 48000 Hz)

Fixes out of sync timestamps in ticket #8762.
Signed-off-by: Marton Balint <cus@passwd.hu>

libavformat/dv.c

@@ -49,7 +49,6 @@ struct DVDemuxContext {
     uint8_t           audio_buf[4][8192];
     int               ach;
     int               frames;
-    uint64_t          abytes;
 };
 
 static inline uint16_t dv_audio_12to16(uint16_t sample)
@@ -258,7 +257,7 @@ static int dv_extract_audio_info(DVDemuxContext *c, const uint8_t *frame)
             c->ast[i] = avformat_new_stream(c->fctx, NULL);
             if (!c->ast[i])
                 break;
-            avpriv_set_pts_info(c->ast[i], 64, 1, 30000);
+            avpriv_set_pts_info(c->ast[i], 64, c->sys->time_base.num, c->sys->time_base.den);
             c->ast[i]->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
             c->ast[i]->codecpar->codec_id   = AV_CODEC_ID_PCM_S16LE;
 
@@ -387,8 +386,7 @@ int avpriv_dv_produce_packet(DVDemuxContext *c, AVPacket *pkt,
     for (i = 0; i < c->ach; i++) {
         c->audio_pkt[i].pos  = pos;
         c->audio_pkt[i].size = size;
-        c->audio_pkt[i].pts  = c->abytes * 30000 * 8 /
-                               c->ast[i]->codecpar->bit_rate;
+        c->audio_pkt[i].pts  = (c->sys->height == 720) ? (c->frames & ~1) : c->frames;
         ppcm[i] = c->audio_buf[i];
     }
     if (c->ach)
@@ -401,10 +399,7 @@ int avpriv_dv_produce_packet(DVDemuxContext *c, AVPacket *pkt,
             c->audio_pkt[2].size = c->audio_pkt[3].size = 0;
         } else {
             c->audio_pkt[0].size = c->audio_pkt[1].size = 0;
-            c->abytes           += size;
         }
-    } else {
-        c->abytes += size;
     }
 
     /* Now it's time to return video packet */
@@ -444,13 +439,6 @@ static int64_t dv_frame_offset(AVFormatContext *s, DVDemuxContext *c,
 void ff_dv_offset_reset(DVDemuxContext *c, int64_t frame_offset)
 {
     c->frames = frame_offset;
-    if (c->ach) {
-        if (c->sys) {
-        c->abytes = av_rescale_q(c->frames, c->sys->time_base,
-                                 (AVRational) { 8, c->ast[0]->codecpar->bit_rate });
-        } else
-            av_log(c->fctx, AV_LOG_ERROR, "cannot adjust audio bytes\n");
-    }
     c->audio_pkt[0].size = c->audio_pkt[1].size = 0;
     c->audio_pkt[2].size = c->audio_pkt[3].size = 0;
 }

tests/ref/seek/lavf-dv

@@ -7,9 +7,9 @@ ret: 0         st: 0 flags:0  ts: 0.800000
 ret: 0         st: 0 flags:1 dts: 0.800000 pts: 0.800000 pos:2880000 size:144000
 ret: 0         st: 0 flags:1  ts:-0.320000
 ret: 0         st: 0 flags:1 dts: 0.000000 pts: 0.000000 pos:      0 size:144000
-ret: 0         st: 1 flags:0  ts: 2.576667
+ret: 0         st: 1 flags:0  ts: 2.560000
 ret: 0         st: 0 flags:1 dts: 0.960000 pts: 0.960000 pos:3456000 size:144000
-ret: 0         st: 1 flags:1  ts: 1.470833
+ret: 0         st: 1 flags:1  ts: 1.480000
 ret: 0         st: 0 flags:1 dts: 0.960000 pts: 0.960000 pos:3456000 size:144000
 ret: 0         st:-1 flags:0  ts: 0.365002
 ret: 0         st: 0 flags:1 dts: 0.360000 pts: 0.360000 pos:1296000 size:144000
@@ -19,9 +19,9 @@ ret: 0         st: 0 flags:0  ts: 2.160000
 ret: 0         st: 0 flags:1 dts: 0.960000 pts: 0.960000 pos:3456000 size:144000
 ret: 0         st: 0 flags:1  ts: 1.040000
 ret: 0         st: 0 flags:1 dts: 0.960000 pts: 0.960000 pos:3456000 size:144000
-ret: 0         st: 1 flags:0  ts:-0.058333
+ret: 0         st: 1 flags:0  ts:-0.040000
 ret: 0         st: 0 flags:1 dts: 0.000000 pts: 0.000000 pos:      0 size:144000
-ret: 0         st: 1 flags:1  ts: 2.835833
+ret: 0         st: 1 flags:1  ts: 2.840000
 ret: 0         st: 0 flags:1 dts: 0.960000 pts: 0.960000 pos:3456000 size:144000
 ret: 0         st:-1 flags:0  ts: 1.730004
 ret: 0         st: 0 flags:1 dts: 0.960000 pts: 0.960000 pos:3456000 size:144000
@@ -31,10 +31,10 @@ ret: 0         st: 0 flags:0  ts:-0.480000
 ret: 0         st: 0 flags:1 dts: 0.000000 pts: 0.000000 pos:      0 size:144000
 ret: 0         st: 0 flags:1  ts: 2.400000
 ret: 0         st: 0 flags:1 dts: 0.960000 pts: 0.960000 pos:3456000 size:144000
-ret: 0         st: 1 flags:0  ts: 1.306667
-ret: 0         st: 0 flags:1 dts: 0.960000 pts: 0.960000 pos:3456000 size:144000
-ret: 0         st: 1 flags:1  ts: 0.200833
+ret: 0         st: 1 flags:0  ts: 1.320000
 ret: 0         st: 0 flags:1 dts: 0.960000 pts: 0.960000 pos:3456000 size:144000
+ret: 0         st: 1 flags:1  ts: 0.200000
+ret: 0         st: 0 flags:1 dts: 0.200000 pts: 0.200000 pos: 720000 size:144000
 ret: 0         st:-1 flags:0  ts:-0.904994
 ret: 0         st: 0 flags:1 dts: 0.000000 pts: 0.000000 pos:      0 size:144000
 ret: 0         st:-1 flags:1  ts: 1.989173
@@ -43,9 +43,9 @@ ret: 0         st: 0 flags:0  ts: 0.880000
 ret: 0         st: 0 flags:1 dts: 0.880000 pts: 0.880000 pos:3168000 size:144000
 ret: 0         st: 0 flags:1  ts:-0.240000
 ret: 0         st: 0 flags:1 dts: 0.000000 pts: 0.000000 pos:      0 size:144000
-ret: 0         st: 1 flags:0  ts: 2.671667
+ret: 0         st: 1 flags:0  ts: 2.680000
 ret: 0         st: 0 flags:1 dts: 0.960000 pts: 0.960000 pos:3456000 size:144000
-ret: 0         st: 1 flags:1  ts: 1.565833
+ret: 0         st: 1 flags:1  ts: 1.560000
 ret: 0         st: 0 flags:1 dts: 0.960000 pts: 0.960000 pos:3456000 size:144000
 ret: 0         st:-1 flags:0  ts: 0.460008
 ret: 0         st: 0 flags:1 dts: 0.480000 pts: 0.480000 pos:1728000 size:144000