Re: [FFmpeg-devel] [PATCH] ivfdec/ivfenc: Match behaviour of libvpx and chromium
On Tue, 2019-10-01 at 13:56 -0400, Calvin Walton wrote: > The ffmpeg code read and wrote a 64bit duration field (in timebase > units) in the ivf > header, where the libvpx and chromium code instead use a 32bit frame > count field, and > then 32bits of unused (reserved?) space. > > Switch ffmpeg to match the behaviour of libvpx & chromium. Just to note (now that I've got fate working on my dev machine again), if this patch is applied, a bunch of the test references will need updates due to the ivf file output changing. I'll include those updates if I do a second patch revision. -- Calvin Walton ___ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-devel] [PATCH] ivfdec/ivfenc: Match behaviour of libvpx and chromium
On Tue, 2019-10-01 at 15:26 -0300, James Almer wrote: > On 10/1/2019 2:56 PM, Calvin Walton wrote: > > libavformat/ivfdec.c | 3 ++- > > libavformat/ivfenc.c | 11 --- > > 2 files changed, 6 insertions(+), 8 deletions(-) > > > > diff --git a/libavformat/ivfdec.c b/libavformat/ivfdec.c > > index 40ae464b76..2eaa5164ff 100644 > > --- a/libavformat/ivfdec.c > > +++ b/libavformat/ivfdec.c > > @@ -53,7 +53,8 @@ static int read_header(AVFormatContext *s) > > st->codecpar->height = avio_rl16(s->pb); > > time_base.den = avio_rl32(s->pb); > > time_base.num = avio_rl32(s->pb); > > -st->duration = avio_rl64(s->pb); > > +st->nb_frames = avio_rl32(s->pb); > > The demuxer will report N/A as duration after this. This is intentional, as the container format doesn't have a duration field, only a frame count. I suppose it might be possible to estimate a duration by probing the file to guess the average framerate, and then dividing the frame count by the framerate - but I'm not familiar with how that could be done in the demuxer > > size_t end = avio_tell(pb); > > > > avio_seek(pb, 24, SEEK_SET); > > -avio_wl64(pb, ctx->frame_cnt * ctx->sum_delta_pts / (ctx- > > >frame_cnt - 1)); > > +avio_wl32(pb, ctx->frame_cnt); > > avio_seek(pb, end, SEEK_SET); > > } > > Similarly, old versions of the ivf demuxer will read bogus duration > values after this change. Old versions of the ivf demuxer read bogus duration values for files generated by vpxenc in the case where the timebase is something other than 1/framerate (i think this can happen if a timebase is manually set or if a fractional framerate is used) or if the file is vfr (I'm not sure if vpxenc can generate vfr files). -- Calvin Walton ___ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-devel] [PATCH] ivfdec/ivfenc: Match behaviour of libvpx and chromium
This is a superset of my patch(es). It should match the behavior of
libvpx more closely, but the validity of the change from duration to
number of frames depends on your interpretation of the reference
implementation, which comments the field as "length".
On Tue, 2019-10-01 at 23:41 +0530, Gyan wrote:
>
> On 01-10-2019 11:26 PM, Calvin Walton wrote:
> > The ffmpeg code read and wrote a 64bit duration field (in timebase
> > units) in the ivf
> > header, where the libvpx and chromium code instead use a 32bit
> > frame count field, and
> > then 32bits of unused (reserved?) space.
> >
> > Switch ffmpeg to match the behaviour of libvpx & chromium.
> >
> > Note that libvpx writes 0 to the frame count field when initially
> > writing the header
> > then seeks back and overwrites it with the real frame count. ffmpeg
> > used to write
> > 0x - I've changed the behaviour to match libvpx.
> >
> > References:
> > https://github.com/webmproject/libvpx/blob/v1.8.1/ivfenc.c#L16
> > Which is called from:
> > https://github.com/webmproject/libvpx/blob/v1.8.1/vpxenc.c#L1191
> > (initial header)
> > https://github.com/webmproject/libvpx/blob/v1.8.1/vpxenc.c#L1209
> > (rewrite with frame count)
> > And the chromium parser:
> > https://chromium.googlesource.com/chromium/src/media/+/1681b9abff73fe0e3d0932aefdab4f039a284d1a/filters/ivf_parser.h
> > ---
> > libavformat/ivfdec.c | 3 ++-
> > libavformat/ivfenc.c | 11 ---
> > 2 files changed, 6 insertions(+), 8 deletions(-)
> >
> > diff --git a/libavformat/ivfdec.c b/libavformat/ivfdec.c
> > index 40ae464b76..2eaa5164ff 100644
> > --- a/libavformat/ivfdec.c
> > +++ b/libavformat/ivfdec.c
> > @@ -53,7 +53,8 @@ static int read_header(AVFormatContext *s)
> > st->codecpar->height = avio_rl16(s->pb);
> > time_base.den = avio_rl32(s->pb);
> > time_base.num = avio_rl32(s->pb);
> > -st->duration = avio_rl64(s->pb);
> > +st->nb_frames = avio_rl32(s->pb);
> > +avio_skip(s->pb, 4); // 32 bits unused
> >
> > st->need_parsing = AVSTREAM_PARSE_HEADERS;
> >
> > diff --git a/libavformat/ivfenc.c b/libavformat/ivfenc.c
> > index adf72117e9..85ca6045ba 100644
> > --- a/libavformat/ivfenc.c
> > +++ b/libavformat/ivfenc.c
> > @@ -22,8 +22,7 @@
> > #include "libavutil/intreadwrite.h"
> >
> > typedef struct IVFEncContext {
> > -unsigned frame_cnt;
> > -uint64_t last_pts, sum_delta_pts;
> > +uint32_t frame_cnt;
> > } IVFEncContext;
> >
> > static int ivf_write_header(AVFormatContext *s)
> > @@ -53,7 +52,8 @@ static int ivf_write_header(AVFormatContext *s)
> > avio_wl16(pb, par->height);
> > avio_wl32(pb, s->streams[0]->time_base.den);
> > avio_wl32(pb, s->streams[0]->time_base.num);
> > -avio_wl64(pb, 0xULL);
> > +avio_wl32(pb, 0); // frame count
> > +avio_wl32(pb, 0); // unused
> >
> > return 0;
> > }
> > @@ -66,10 +66,7 @@ static int ivf_write_packet(AVFormatContext *s,
> > AVPacket *pkt)
> > avio_wl32(pb, pkt->size);
> > avio_wl64(pb, pkt->pts);
> > avio_write(pb, pkt->data, pkt->size);
> > -if (ctx->frame_cnt)
> > -ctx->sum_delta_pts += pkt->pts - ctx->last_pts;
> > ctx->frame_cnt++;
> > -ctx->last_pts = pkt->pts;
> >
> > return 0;
> > }
> > @@ -83,7 +80,7 @@ static int ivf_write_trailer(AVFormatContext *s)
> > size_t end = avio_tell(pb);
> >
> > avio_seek(pb, 24, SEEK_SET);
> > -avio_wl64(pb, ctx->frame_cnt * ctx->sum_delta_pts / (ctx-
> > >frame_cnt - 1));
> > +avio_wl32(pb, ctx->frame_cnt);
> > avio_seek(pb, end, SEEK_SET);
> > }
>
> See
> http://www.ffmpeg.org/pipermail/ffmpeg-devel/2019-October/250871.html
>
> Gyan
> ___
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Re: [FFmpeg-devel] [PATCH] ivfdec/ivfenc: Match behaviour of libvpx and chromium
On 01-10-2019 11:53 PM, James Almer wrote:
On 10/1/2019 3:11 PM, Gyan wrote:
On 01-10-2019 11:26 PM, Calvin Walton wrote:
The ffmpeg code read and wrote a 64bit duration field (in timebase
units) in the ivf
header, where the libvpx and chromium code instead use a 32bit frame
count field, and
then 32bits of unused (reserved?) space.
Switch ffmpeg to match the behaviour of libvpx & chromium.
Note that libvpx writes 0 to the frame count field when initially
writing the header
then seeks back and overwrites it with the real frame count. ffmpeg
used to write
0x - I've changed the behaviour to match libvpx.
References:
https://github.com/webmproject/libvpx/blob/v1.8.1/ivfenc.c#L16
Which is called from:
https://github.com/webmproject/libvpx/blob/v1.8.1/vpxenc.c#L1191
(initial header)
https://github.com/webmproject/libvpx/blob/v1.8.1/vpxenc.c#L1209
(rewrite with frame count)
And the chromium parser:
https://chromium.googlesource.com/chromium/src/media/+/1681b9abff73fe0e3d0932aefdab4f039a284d1a/filters/ivf_parser.h
---
libavformat/ivfdec.c | 3 ++-
libavformat/ivfenc.c | 11 ---
2 files changed, 6 insertions(+), 8 deletions(-)
diff --git a/libavformat/ivfdec.c b/libavformat/ivfdec.c
index 40ae464b76..2eaa5164ff 100644
--- a/libavformat/ivfdec.c
+++ b/libavformat/ivfdec.c
@@ -53,7 +53,8 @@ static int read_header(AVFormatContext *s)
st->codecpar->height = avio_rl16(s->pb);
time_base.den = avio_rl32(s->pb);
time_base.num = avio_rl32(s->pb);
- st->duration = avio_rl64(s->pb);
+ st->nb_frames = avio_rl32(s->pb);
+ avio_skip(s->pb, 4); // 32 bits unused
st->need_parsing = AVSTREAM_PARSE_HEADERS;
diff --git a/libavformat/ivfenc.c b/libavformat/ivfenc.c
index adf72117e9..85ca6045ba 100644
--- a/libavformat/ivfenc.c
+++ b/libavformat/ivfenc.c
@@ -22,8 +22,7 @@
#include "libavutil/intreadwrite.h"
typedef struct IVFEncContext {
- unsigned frame_cnt;
- uint64_t last_pts, sum_delta_pts;
+ uint32_t frame_cnt;
} IVFEncContext;
static int ivf_write_header(AVFormatContext *s)
@@ -53,7 +52,8 @@ static int ivf_write_header(AVFormatContext *s)
avio_wl16(pb, par->height);
avio_wl32(pb, s->streams[0]->time_base.den);
avio_wl32(pb, s->streams[0]->time_base.num);
- avio_wl64(pb, 0xULL);
+ avio_wl32(pb, 0); // frame count
+ avio_wl32(pb, 0); // unused
return 0;
}
@@ -66,10 +66,7 @@ static int ivf_write_packet(AVFormatContext *s,
AVPacket *pkt)
avio_wl32(pb, pkt->size);
avio_wl64(pb, pkt->pts);
avio_write(pb, pkt->data, pkt->size);
- if (ctx->frame_cnt)
- ctx->sum_delta_pts += pkt->pts - ctx->last_pts;
ctx->frame_cnt++;
- ctx->last_pts = pkt->pts;
return 0;
}
@@ -83,7 +80,7 @@ static int ivf_write_trailer(AVFormatContext *s)
size_t end = avio_tell(pb);
avio_seek(pb, 24, SEEK_SET);
- avio_wl64(pb, ctx->frame_cnt * ctx->sum_delta_pts /
(ctx->frame_cnt - 1));
+ avio_wl32(pb, ctx->frame_cnt);
avio_seek(pb, end, SEEK_SET);
}
See http://www.ffmpeg.org/pipermail/ffmpeg-devel/2019-October/250871.html
Gyan
That patch was already NAKed, and a fixed version sent in replacement.
I intended to link to the start of the thread, not the patch.
Gyan
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Re: [FFmpeg-devel] [PATCH] ivfdec/ivfenc: Match behaviour of libvpx and chromium
On 10/1/2019 2:56 PM, Calvin Walton wrote:
> The ffmpeg code read and wrote a 64bit duration field (in timebase units) in
> the ivf
> header, where the libvpx and chromium code instead use a 32bit frame count
> field, and
> then 32bits of unused (reserved?) space.
>
> Switch ffmpeg to match the behaviour of libvpx & chromium.
>
> Note that libvpx writes 0 to the frame count field when initially writing the
> header
> then seeks back and overwrites it with the real frame count. ffmpeg used to
> write
> 0x - I've changed the behaviour to match libvpx.
>
> References:
> https://github.com/webmproject/libvpx/blob/v1.8.1/ivfenc.c#L16
> Which is called from:
> https://github.com/webmproject/libvpx/blob/v1.8.1/vpxenc.c#L1191 (initial
> header)
> https://github.com/webmproject/libvpx/blob/v1.8.1/vpxenc.c#L1209 (rewrite
> with frame count)
> And the chromium parser:
> https://chromium.googlesource.com/chromium/src/media/+/1681b9abff73fe0e3d0932aefdab4f039a284d1a/filters/ivf_parser.h
> ---
> libavformat/ivfdec.c | 3 ++-
> libavformat/ivfenc.c | 11 ---
> 2 files changed, 6 insertions(+), 8 deletions(-)
>
> diff --git a/libavformat/ivfdec.c b/libavformat/ivfdec.c
> index 40ae464b76..2eaa5164ff 100644
> --- a/libavformat/ivfdec.c
> +++ b/libavformat/ivfdec.c
> @@ -53,7 +53,8 @@ static int read_header(AVFormatContext *s)
> st->codecpar->height = avio_rl16(s->pb);
> time_base.den = avio_rl32(s->pb);
> time_base.num = avio_rl32(s->pb);
> -st->duration = avio_rl64(s->pb);
> +st->nb_frames = avio_rl32(s->pb);
The demuxer will report N/A as duration after this.
> +avio_skip(s->pb, 4); // 32 bits unused
>
> st->need_parsing = AVSTREAM_PARSE_HEADERS;
>
> diff --git a/libavformat/ivfenc.c b/libavformat/ivfenc.c
> index adf72117e9..85ca6045ba 100644
> --- a/libavformat/ivfenc.c
> +++ b/libavformat/ivfenc.c
> @@ -22,8 +22,7 @@
> #include "libavutil/intreadwrite.h"
>
> typedef struct IVFEncContext {
> -unsigned frame_cnt;
> -uint64_t last_pts, sum_delta_pts;
> +uint32_t frame_cnt;
> } IVFEncContext;
>
> static int ivf_write_header(AVFormatContext *s)
> @@ -53,7 +52,8 @@ static int ivf_write_header(AVFormatContext *s)
> avio_wl16(pb, par->height);
> avio_wl32(pb, s->streams[0]->time_base.den);
> avio_wl32(pb, s->streams[0]->time_base.num);
> -avio_wl64(pb, 0xULL);
> +avio_wl32(pb, 0); // frame count
> +avio_wl32(pb, 0); // unused
>
> return 0;
> }
> @@ -66,10 +66,7 @@ static int ivf_write_packet(AVFormatContext *s, AVPacket
> *pkt)
> avio_wl32(pb, pkt->size);
> avio_wl64(pb, pkt->pts);
> avio_write(pb, pkt->data, pkt->size);
> -if (ctx->frame_cnt)
> -ctx->sum_delta_pts += pkt->pts - ctx->last_pts;
> ctx->frame_cnt++;
> -ctx->last_pts = pkt->pts;
>
> return 0;
> }
> @@ -83,7 +80,7 @@ static int ivf_write_trailer(AVFormatContext *s)
> size_t end = avio_tell(pb);
>
> avio_seek(pb, 24, SEEK_SET);
> -avio_wl64(pb, ctx->frame_cnt * ctx->sum_delta_pts / (ctx->frame_cnt
> - 1));
> +avio_wl32(pb, ctx->frame_cnt);
> avio_seek(pb, end, SEEK_SET);
> }
Similarly, old versions of the ivf demuxer will read bogus duration
values after this change.
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Re: [FFmpeg-devel] [PATCH] ivfdec/ivfenc: Match behaviour of libvpx and chromium
On 10/1/2019 3:11 PM, Gyan wrote:
>
>
> On 01-10-2019 11:26 PM, Calvin Walton wrote:
>> The ffmpeg code read and wrote a 64bit duration field (in timebase
>> units) in the ivf
>> header, where the libvpx and chromium code instead use a 32bit frame
>> count field, and
>> then 32bits of unused (reserved?) space.
>>
>> Switch ffmpeg to match the behaviour of libvpx & chromium.
>>
>> Note that libvpx writes 0 to the frame count field when initially
>> writing the header
>> then seeks back and overwrites it with the real frame count. ffmpeg
>> used to write
>> 0x - I've changed the behaviour to match libvpx.
>>
>> References:
>> https://github.com/webmproject/libvpx/blob/v1.8.1/ivfenc.c#L16
>> Which is called from:
>> https://github.com/webmproject/libvpx/blob/v1.8.1/vpxenc.c#L1191
>> (initial header)
>> https://github.com/webmproject/libvpx/blob/v1.8.1/vpxenc.c#L1209
>> (rewrite with frame count)
>> And the chromium parser:
>> https://chromium.googlesource.com/chromium/src/media/+/1681b9abff73fe0e3d0932aefdab4f039a284d1a/filters/ivf_parser.h
>>
>> ---
>> libavformat/ivfdec.c | 3 ++-
>> libavformat/ivfenc.c | 11 ---
>> 2 files changed, 6 insertions(+), 8 deletions(-)
>>
>> diff --git a/libavformat/ivfdec.c b/libavformat/ivfdec.c
>> index 40ae464b76..2eaa5164ff 100644
>> --- a/libavformat/ivfdec.c
>> +++ b/libavformat/ivfdec.c
>> @@ -53,7 +53,8 @@ static int read_header(AVFormatContext *s)
>> st->codecpar->height = avio_rl16(s->pb);
>> time_base.den = avio_rl32(s->pb);
>> time_base.num = avio_rl32(s->pb);
>> - st->duration = avio_rl64(s->pb);
>> + st->nb_frames = avio_rl32(s->pb);
>> + avio_skip(s->pb, 4); // 32 bits unused
>> st->need_parsing = AVSTREAM_PARSE_HEADERS;
>> diff --git a/libavformat/ivfenc.c b/libavformat/ivfenc.c
>> index adf72117e9..85ca6045ba 100644
>> --- a/libavformat/ivfenc.c
>> +++ b/libavformat/ivfenc.c
>> @@ -22,8 +22,7 @@
>> #include "libavutil/intreadwrite.h"
>> typedef struct IVFEncContext {
>> - unsigned frame_cnt;
>> - uint64_t last_pts, sum_delta_pts;
>> + uint32_t frame_cnt;
>> } IVFEncContext;
>> static int ivf_write_header(AVFormatContext *s)
>> @@ -53,7 +52,8 @@ static int ivf_write_header(AVFormatContext *s)
>> avio_wl16(pb, par->height);
>> avio_wl32(pb, s->streams[0]->time_base.den);
>> avio_wl32(pb, s->streams[0]->time_base.num);
>> - avio_wl64(pb, 0xULL);
>> + avio_wl32(pb, 0); // frame count
>> + avio_wl32(pb, 0); // unused
>> return 0;
>> }
>> @@ -66,10 +66,7 @@ static int ivf_write_packet(AVFormatContext *s,
>> AVPacket *pkt)
>> avio_wl32(pb, pkt->size);
>> avio_wl64(pb, pkt->pts);
>> avio_write(pb, pkt->data, pkt->size);
>> - if (ctx->frame_cnt)
>> - ctx->sum_delta_pts += pkt->pts - ctx->last_pts;
>> ctx->frame_cnt++;
>> - ctx->last_pts = pkt->pts;
>> return 0;
>> }
>> @@ -83,7 +80,7 @@ static int ivf_write_trailer(AVFormatContext *s)
>> size_t end = avio_tell(pb);
>> avio_seek(pb, 24, SEEK_SET);
>> - avio_wl64(pb, ctx->frame_cnt * ctx->sum_delta_pts /
>> (ctx->frame_cnt - 1));
>> + avio_wl32(pb, ctx->frame_cnt);
>> avio_seek(pb, end, SEEK_SET);
>> }
>
> See http://www.ffmpeg.org/pipermail/ffmpeg-devel/2019-October/250871.html
>
> Gyan
That patch was already NAKed, and a fixed version sent in replacement.
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Re: [FFmpeg-devel] [PATCH] ivfdec/ivfenc: Match behaviour of libvpx and chromium
On 01-10-2019 11:26 PM, Calvin Walton wrote:
The ffmpeg code read and wrote a 64bit duration field (in timebase units) in
the ivf
header, where the libvpx and chromium code instead use a 32bit frame count
field, and
then 32bits of unused (reserved?) space.
Switch ffmpeg to match the behaviour of libvpx & chromium.
Note that libvpx writes 0 to the frame count field when initially writing the
header
then seeks back and overwrites it with the real frame count. ffmpeg used to
write
0x - I've changed the behaviour to match libvpx.
References:
https://github.com/webmproject/libvpx/blob/v1.8.1/ivfenc.c#L16
Which is called from:
https://github.com/webmproject/libvpx/blob/v1.8.1/vpxenc.c#L1191 (initial
header)
https://github.com/webmproject/libvpx/blob/v1.8.1/vpxenc.c#L1209 (rewrite with
frame count)
And the chromium parser:
https://chromium.googlesource.com/chromium/src/media/+/1681b9abff73fe0e3d0932aefdab4f039a284d1a/filters/ivf_parser.h
---
libavformat/ivfdec.c | 3 ++-
libavformat/ivfenc.c | 11 ---
2 files changed, 6 insertions(+), 8 deletions(-)
diff --git a/libavformat/ivfdec.c b/libavformat/ivfdec.c
index 40ae464b76..2eaa5164ff 100644
--- a/libavformat/ivfdec.c
+++ b/libavformat/ivfdec.c
@@ -53,7 +53,8 @@ static int read_header(AVFormatContext *s)
st->codecpar->height = avio_rl16(s->pb);
time_base.den = avio_rl32(s->pb);
time_base.num = avio_rl32(s->pb);
-st->duration = avio_rl64(s->pb);
+st->nb_frames = avio_rl32(s->pb);
+avio_skip(s->pb, 4); // 32 bits unused
st->need_parsing = AVSTREAM_PARSE_HEADERS;
diff --git a/libavformat/ivfenc.c b/libavformat/ivfenc.c
index adf72117e9..85ca6045ba 100644
--- a/libavformat/ivfenc.c
+++ b/libavformat/ivfenc.c
@@ -22,8 +22,7 @@
#include "libavutil/intreadwrite.h"
typedef struct IVFEncContext {
-unsigned frame_cnt;
-uint64_t last_pts, sum_delta_pts;
+uint32_t frame_cnt;
} IVFEncContext;
static int ivf_write_header(AVFormatContext *s)
@@ -53,7 +52,8 @@ static int ivf_write_header(AVFormatContext *s)
avio_wl16(pb, par->height);
avio_wl32(pb, s->streams[0]->time_base.den);
avio_wl32(pb, s->streams[0]->time_base.num);
-avio_wl64(pb, 0xULL);
+avio_wl32(pb, 0); // frame count
+avio_wl32(pb, 0); // unused
return 0;
}
@@ -66,10 +66,7 @@ static int ivf_write_packet(AVFormatContext *s, AVPacket
*pkt)
avio_wl32(pb, pkt->size);
avio_wl64(pb, pkt->pts);
avio_write(pb, pkt->data, pkt->size);
-if (ctx->frame_cnt)
-ctx->sum_delta_pts += pkt->pts - ctx->last_pts;
ctx->frame_cnt++;
-ctx->last_pts = pkt->pts;
return 0;
}
@@ -83,7 +80,7 @@ static int ivf_write_trailer(AVFormatContext *s)
size_t end = avio_tell(pb);
avio_seek(pb, 24, SEEK_SET);
-avio_wl64(pb, ctx->frame_cnt * ctx->sum_delta_pts / (ctx->frame_cnt -
1));
+avio_wl32(pb, ctx->frame_cnt);
avio_seek(pb, end, SEEK_SET);
}
See http://www.ffmpeg.org/pipermail/ffmpeg-devel/2019-October/250871.html
Gyan
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[FFmpeg-devel] [PATCH] ivfdec/ivfenc: Match behaviour of libvpx and chromium
The ffmpeg code read and wrote a 64bit duration field (in timebase units) in
the ivf
header, where the libvpx and chromium code instead use a 32bit frame count
field, and
then 32bits of unused (reserved?) space.
Switch ffmpeg to match the behaviour of libvpx & chromium.
Note that libvpx writes 0 to the frame count field when initially writing the
header
then seeks back and overwrites it with the real frame count. ffmpeg used to
write
0x - I've changed the behaviour to match libvpx.
References:
https://github.com/webmproject/libvpx/blob/v1.8.1/ivfenc.c#L16
Which is called from:
https://github.com/webmproject/libvpx/blob/v1.8.1/vpxenc.c#L1191 (initial
header)
https://github.com/webmproject/libvpx/blob/v1.8.1/vpxenc.c#L1209 (rewrite with
frame count)
And the chromium parser:
https://chromium.googlesource.com/chromium/src/media/+/1681b9abff73fe0e3d0932aefdab4f039a284d1a/filters/ivf_parser.h
---
libavformat/ivfdec.c | 3 ++-
libavformat/ivfenc.c | 11 ---
2 files changed, 6 insertions(+), 8 deletions(-)
diff --git a/libavformat/ivfdec.c b/libavformat/ivfdec.c
index 40ae464b76..2eaa5164ff 100644
--- a/libavformat/ivfdec.c
+++ b/libavformat/ivfdec.c
@@ -53,7 +53,8 @@ static int read_header(AVFormatContext *s)
st->codecpar->height = avio_rl16(s->pb);
time_base.den = avio_rl32(s->pb);
time_base.num = avio_rl32(s->pb);
-st->duration = avio_rl64(s->pb);
+st->nb_frames = avio_rl32(s->pb);
+avio_skip(s->pb, 4); // 32 bits unused
st->need_parsing = AVSTREAM_PARSE_HEADERS;
diff --git a/libavformat/ivfenc.c b/libavformat/ivfenc.c
index adf72117e9..85ca6045ba 100644
--- a/libavformat/ivfenc.c
+++ b/libavformat/ivfenc.c
@@ -22,8 +22,7 @@
#include "libavutil/intreadwrite.h"
typedef struct IVFEncContext {
-unsigned frame_cnt;
-uint64_t last_pts, sum_delta_pts;
+uint32_t frame_cnt;
} IVFEncContext;
static int ivf_write_header(AVFormatContext *s)
@@ -53,7 +52,8 @@ static int ivf_write_header(AVFormatContext *s)
avio_wl16(pb, par->height);
avio_wl32(pb, s->streams[0]->time_base.den);
avio_wl32(pb, s->streams[0]->time_base.num);
-avio_wl64(pb, 0xULL);
+avio_wl32(pb, 0); // frame count
+avio_wl32(pb, 0); // unused
return 0;
}
@@ -66,10 +66,7 @@ static int ivf_write_packet(AVFormatContext *s, AVPacket
*pkt)
avio_wl32(pb, pkt->size);
avio_wl64(pb, pkt->pts);
avio_write(pb, pkt->data, pkt->size);
-if (ctx->frame_cnt)
-ctx->sum_delta_pts += pkt->pts - ctx->last_pts;
ctx->frame_cnt++;
-ctx->last_pts = pkt->pts;
return 0;
}
@@ -83,7 +80,7 @@ static int ivf_write_trailer(AVFormatContext *s)
size_t end = avio_tell(pb);
avio_seek(pb, 24, SEEK_SET);
-avio_wl64(pb, ctx->frame_cnt * ctx->sum_delta_pts / (ctx->frame_cnt -
1));
+avio_wl32(pb, ctx->frame_cnt);
avio_seek(pb, end, SEEK_SET);
}
--
2.21.0
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