Current code will call avpriv_set_pts_info() for each video frame,
possibly setting a different timebase if the stream framerate changes.
This violates API conventions, as the timebase is supposed to stay
constant after stream creation.
Change the demuxer to set a single timebase that is fine enough to
handle all supported DV framerates.
The seek tests change slightly because the new timebase is more
granular.
---
libavcodec/dv.h | 3 +++
libavformat/dv.c | 25 -
tests/ref/seek/lavf-dv| 16
tests/ref/seek/vsynth_lena-dv | 24
tests/ref/seek/vsynth_lena-dv-411 | 24
tests/ref/seek/vsynth_lena-dv-50 | 24
6 files changed, 67 insertions(+), 49 deletions(-)
diff --git a/libavcodec/dv.h b/libavcodec/dv.h
index 29f97b6089a..b473bdc992d 100644
--- a/libavcodec/dv.h
+++ b/libavcodec/dv.h
@@ -60,6 +60,9 @@ enum DVPackType {
*/
#define DV_MAX_FRAME_SIZE 576000
+// LCM of video framerate numerators
+#define DV_TIMESCALE_VIDEO 6
+
/**
* maximum number of blocks per macroblock in any DV format
*/
diff --git a/libavformat/dv.c b/libavformat/dv.c
index ffed1a7a90e..d30dc298805 100644
--- a/libavformat/dv.c
+++ b/libavformat/dv.c
@@ -69,6 +69,8 @@ struct DVDemuxContext {
uint8_t audio_buf[4][8192];
int ach;
int frames;
+
+int64_t next_pts_video;
};
static inline uint16_t dv_audio_12to16(uint16_t sample)
@@ -314,8 +316,6 @@ static int dv_extract_video_info(DVDemuxContext *c, const
uint8_t *frame)
par = c->vst->codecpar;
-avpriv_set_pts_info(c->vst, 64, c->sys->time_base.num,
-c->sys->time_base.den);
c->vst->avg_frame_rate = av_inv_q(c->vst->time_base);
/* finding out SAR is a little bit messy */
@@ -360,6 +360,8 @@ static int dv_init_demux(AVFormatContext *s, DVDemuxContext
*c)
c->vst->codecpar->bit_rate = 2500;
c->vst->start_time= 0;
+avpriv_set_pts_info(c->vst, 64, 1, DV_TIMESCALE_VIDEO);
+
/* Audio streams are added later as they are encountered. */
s->ctx_flags |= AVFMTCTX_NOHEADER;
@@ -463,7 +465,10 @@ int avpriv_dv_produce_packet(DVDemuxContext *c, AVPacket
*pkt,
pkt->size = size;
pkt->flags |= AV_PKT_FLAG_KEY;
pkt->stream_index = c->vst->index;
-pkt->pts = c->frames;
+pkt->pts = c->next_pts_video;
+pkt->duration = av_rescale_q(1, c->sys->time_base,
c->vst->time_base);
+
+c->next_pts_video += pkt->duration;
}
c->frames++;
@@ -477,11 +482,12 @@ static int64_t dv_frame_offset(AVFormatContext *s,
DVDemuxContext *c,
// FIXME: sys may be wrong if last dv_read_packet() failed (buffer is junk)
FFFormatContext *const si = ffformatcontext(s);
const int frame_size = c->sys->frame_size;
+int64_t frame_count = av_rescale_q(timestamp, c->vst->time_base,
c->sys->time_base);
int64_t offset;
int64_t size = avio_size(s->pb) - si->data_offset;
int64_t max_offset = ((size - 1) / frame_size) * frame_size;
-offset = frame_size * timestamp;
+offset = frame_size * frame_count;
if (size >= 0 && offset > max_offset)
offset = max_offset;
@@ -494,6 +500,8 @@ 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->sys)
+c->next_pts_video = av_rescale_q(frame_offset, c->sys->time_base,
c->vst->time_base);
c->audio_pkt[0].size = c->audio_pkt[1].size = 0;
c->audio_pkt[2].size = c->audio_pkt[3].size = 0;
}
@@ -618,7 +626,14 @@ static int dv_read_seek(AVFormatContext *s, int
stream_index,
{
RawDVContext *r = s->priv_data;
DVDemuxContext *c = >dv_demux;
-int64_t offset= dv_frame_offset(s, c, timestamp, flags);
+int64_t offset;
+
+// seek using the video stream
+if (stream_index != c->vst->index)
+timestamp = av_rescale_q(timestamp,
s->streams[stream_index]->time_base,
+ c->vst->time_base);
+
+offset = dv_frame_offset(s, c, timestamp, flags);
if (avio_seek(s->pb, offset, SEEK_SET) < 0)
return -1;
diff --git a/tests/ref/seek/lavf-dv b/tests/ref/seek/lavf-dv
index f63e4460be6..95f19d28f03 100644
--- a/tests/ref/seek/lavf-dv
+++ b/tests/ref/seek/lavf-dv
@@ -3,9 +3,9 @@ ret: 0 st:-1 flags:0 ts:-1.00
ret: 0 st: 0 flags:1 dts: 0.00 pts: 0.00 pos: 0
size:144000
ret: 0 st:-1 flags:1 ts: 1.894167
ret: 0 st: 0 flags:1 dts: 0.96 pts: 0.96 pos:3456000
size:144000
-ret: 0 st: 0 flags:0 ts: 0.80
+ret: 0 st: 0 flags:0 ts: 0.788333
ret: 0 st: 0 flags:1 dts: 0.80 pts: 0.80 pos:288
size:144000
-ret: 0
