[FFmpeg-devel] Create and populate AVStream side data packet with contents of ISOBMFF edit list entries

[Matthew Szatmary]

Create and populate AVStream side data packet with contents of ISOBMFF
edit list entries

Signed-off-by: Matthew Szatmary <matt at szatmary.org>
---
 Changelog           |  1 +
 libavcodec/packet.h | 15 +++++++++++++++
 libavformat/mov.c   | 15 +++++++++++++++
 3 files changed, 31 insertions(+)

diff --git a/Changelog b/Changelog
index 6f648bff2b..d51e836301 100644
--- a/Changelog
+++ b/Changelog
@@ -10,6 +10,7 @@ version <next>:
 - ADPCM IMA Ubisoft APM encoder
 - Rayman 2 APM muxer
 - AV1 encoding support SVT-AV1
+- AV_PKT_DATA_EDIT_LIST added to AVStream side_data


 version 4.3:
diff --git a/libavcodec/packet.h b/libavcodec/packet.h
index 0a19a0eff3..1f0e3405ed 100644
--- a/libavcodec/packet.h
+++ b/libavcodec/packet.h
@@ -290,6 +290,21 @@ enum AVPacketSideDataType {
      */
     AV_PKT_DATA_S12M_TIMECODE,

+    /**
+     * ISO media file edit list side data packet
+     * The structre is repeated for each entry in the edit list
+     * The number of entries can be calculated
+     * by dividing the total size by the entry size
+     * Each entry is 20 bytes and is laid out as follows:
+     * @code
+     * s64be segment duration
+     * s64be media time
+     * s16be media rate
+     * s16be media rate fraction
+     * @endcode
+     */
+    AV_PKT_DATA_EDIT_LIST,
+
     /**
      * The number of side data types.
      * This is not part of the public API/ABI in the sense that it may
diff --git a/libavformat/mov.c b/libavformat/mov.c
index d16840f3df..fbfcdddf3f 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -4311,6 +4311,21 @@ static int mov_read_trak(MOVContext *c,
AVIOContext *pb, MOVAtom atom)
         && sc->time_scale == st->codecpar->sample_rate) {
             st->need_parsing = AVSTREAM_PARSE_FULL;
     }
+
+    if (sc->elst_data) {
+        int i;
+        uint8_t *elst_data;
+        elst_data = av_stream_new_side_data(st,
AV_PKT_DATA_EDIT_LIST, sc->elst_count * 20);
+        if (elst_data) {
+            for (i = 0; i < sc->elst_count; i++) {
+                uint32_t media_rate = (uint32_t)sc->elst_data[i].rate
* 65536.0;
+                AV_WB64((elst_data+(i*20)), sc->elst_data[i].duration);
+                AV_WB64((elst_data+(i*20)+8), sc->elst_data[i].time);
+                AV_WB32((elst_data+(i*20)+16), media_rate);
+            }
+        }
+    }
+
     /* Do not need those anymore. */
     av_freep(&sc->chunk_offsets);
     av_freep(&sc->sample_sizes);
-- 
2.27.0

On Wed, Jul 29, 2020 at 3:56 PM Matthew Szatmary <matt at szatmary.org> wrote:
>
> On Wed, Jul 29, 2020 at 12:22 PM Andreas Rheinhardt
> <andreas.rheinhardt at gmail.com> wrote:
> >
> > Matthew Szatmary:
> > > Create and populate AVStream side data packet with contents of ISOBMFF
> > > edit list entries
> > >
> > > Signed-off-by: Matthew Szatmary <matt at szatmary.org>
> > > ---
> > >  Changelog           |  1 +
> > >  libavcodec/packet.h | 14 ++++++++++++++
> > >  libavformat/mov.c   | 17 ++++++++++++++++-
> > >  3 files changed, 31 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/Changelog b/Changelog
> > > index c37ffa82e1..2d719dd3b1 100644
> > > --- a/Changelog
> > > +++ b/Changelog
> > > @@ -9,6 +9,7 @@ version <next>:
> > >  - VDPAU accelerated HEVC 10/12bit decoding
> > >  - ADPCM IMA Ubisoft APM encoder
> > >  - Rayman 2 APM muxer
> > > +- AV_PKT_DATA_EDIT_LIST added to AVStream side_data
> > >
> > >
> > >  version 4.3:
> > > diff --git a/libavcodec/packet.h b/libavcodec/packet.h
> > > index 0a19a0eff3..5faa594cf5 100644
> > > --- a/libavcodec/packet.h
> > > +++ b/libavcodec/packet.h
> > > @@ -290,6 +290,20 @@ enum AVPacketSideDataType {
> > >       */
> > >      AV_PKT_DATA_S12M_TIMECODE,
> > >
> > > +    /**
> > > +     * ISO media file edit list side data packet
> > > +     * The structure is repeated for each entry in the edit list
> > > +     * The number of entries can be calculated
> > > +     * by dividing the packet size by the entry size
> > > +     * Each entry is 20 bytes and is laid out as follows:
> > > +     * @code
> > > +     * s64le     duration
> > > +     * s64le     time
> > > +     * float32le rate
> Good point, I will make that change.
>
> >
> > You are obviously copying the MOVElst structure; yet the rate is a 16.16
> > fixed point number in the file and not a float, so one should probably
> > use this.
> >
> > > +     * @endcode
> > > +     */
> > > +    AV_PKT_DATA_EDIT_LIST,
> > > +
> > >      /**
> > >       * The number of side data types.
> > >       * This is not part of the public API/ABI in the sense that it may
> > > diff --git a/libavformat/mov.c b/libavformat/mov.c
> > > index d16840f3df..bb2c940e80 100644
> > > --- a/libavformat/mov.c
> > > +++ b/libavformat/mov.c
> > > @@ -4317,7 +4317,6 @@ static int mov_read_trak(MOVContext *c,
> > > AVIOContext *pb, MOVAtom atom)
> > >      av_freep(&sc->keyframes);
> > >      av_freep(&sc->stts_data);
> > >      av_freep(&sc->stps_data);
> > > -    av_freep(&sc->elst_data);
> >
> > This is still needed, namely if an error happens before you can attach
> > the stream side-data. E.g. if an invalid edit list is found and
> > standards compliance is set to strict. Or if av_stream_new_side_data()
> > fails.
>
> av_freep(&sc->elst_data); is also called in mov_read_close, So it
> would only leak if the API was used incorrectly. But that said, I
> think I can move the logic to mov_read_trak, and make the whole point
> moot. I was just trying to keep it near the other side_data calls.
>
> >
> > >      av_freep(&sc->rap_group);
> > >
> > >      return 0;
> > > @@ -7662,6 +7661,22 @@ static int mov_read_header(AVFormatContext *s)
> > >          AVStream *st = s->streams[i];
> > >          MOVStreamContext *sc = st->priv_data;
> > >
> > > +        if (sc->elst_data) {
> > > +            uint8_t *elst_data;
> > > +            elst_data = av_stream_new_side_data(st,
> > > AV_PKT_DATA_EDIT_LIST, sc->elst_count * 20);
> >
> > I wonder whether it would be advantageouos to use
> > av_stream_add_side_data() here.
>
> av_stream_new_side_data is just a wrapper for av_malloc +
> av_stream_add_side_data
>
> > > +
> > > +            if (!elst_data)
> > > +                goto fail;
> > > +
> > > +            for (j = 0; j < sc->elst_count; j++) {
> > > +                AV_WB64((elst_data+(j*20)), sc->elst_data[j].duration);
> > > +                AV_WB64((elst_data+(j*20)+8), sc->elst_data[j].time);
> >
> > "WB" stands for "Write Big-endian", yet your documentation says that it
> > is supposed to be little-endian.
>
> thanks, new patch included
>
>
> >
> > > +                AV_WB32((elst_data+(j*20)+16), sc->elst_data[j].rate);
> > > +            }
> > > +
> > > +            av_freep(&sc->elst_data);
> > > +        }
> > > +
> > >          switch (st->codecpar->codec_type) {
> > >          case AVMEDIA_TYPE_AUDIO:
> > >              err = ff_replaygain_export(st, s->metadata);
> > >
> >
> > _______________________________________________
> > ffmpeg-devel mailing list
> > ffmpeg-devel at ffmpeg.org
> > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> >
> > To unsubscribe, visit link above, or email
> > ffmpeg-devel-request at ffmpeg.org with subject "unsubscribe".
>
>
> Create and populate AVStream side data packet with contents of ISOBMFF
> edit list entries
>
> Signed-off-by: Matthew Szatmary <matt at szatmary.org>
> ---
>  Changelog           |  1 +
>  libavcodec/packet.h | 15 +++++++++++++++
>  libavformat/mov.c   | 15 +++++++++++++++
>  3 files changed, 31 insertions(+)
>
> diff --git a/Changelog b/Changelog
> index 6f648bff2b..d51e836301 100644
> --- a/Changelog
> +++ b/Changelog
> @@ -10,6 +10,7 @@ version <next>:
>  - ADPCM IMA Ubisoft APM encoder
>  - Rayman 2 APM muxer
>  - AV1 encoding support SVT-AV1
> +- AV_PKT_DATA_EDIT_LIST added to AVStream side_data
>
>
>  version 4.3:
> diff --git a/libavcodec/packet.h b/libavcodec/packet.h
> index 0a19a0eff3..1f0e3405ed 100644
> --- a/libavcodec/packet.h
> +++ b/libavcodec/packet.h
> @@ -290,6 +290,21 @@ enum AVPacketSideDataType {
>       */
>      AV_PKT_DATA_S12M_TIMECODE,
>
> +    /**
> +     * ISO media file edit list side data packet
> +     * The structure is repeated for each entry in the edit list
> +     * The number of entries can be calculated
> +     * by dividing the packet size by the entry size
> +     * Each entry is 20 bytes and is laid out as follows:
> +     * @code
> +     * s64be segment duration
> +     * s64be media time
> +     * s16be media rate
> +     * s16be media rate fraction
> +     * @endcode
> +     */
> +    AV_PKT_DATA_EDIT_LIST,
> +
>      /**
>       * The number of side data types.
>       * This is not part of the public API/ABI in the sense that it may
> diff --git a/libavformat/mov.c b/libavformat/mov.c
> index d16840f3df..fbfcdddf3f 100644
> --- a/libavformat/mov.c
> +++ b/libavformat/mov.c
> @@ -4311,6 +4311,21 @@ static int mov_read_trak(MOVContext *c,
> AVIOContext *pb, MOVAtom atom)
>          && sc->time_scale == st->codecpar->sample_rate) {
>              st->need_parsing = AVSTREAM_PARSE_FULL;
>      }
> +
> +    if (sc->elst_data) {
> +        int i;
> +        uint8_t *elst_data;
> +        elst_data = av_stream_new_side_data(st,
> AV_PKT_DATA_EDIT_LIST, sc->elst_count * 20);
> +        if (elst_data) {
> +            for (i = 0; i < sc->elst_count; i++) {
> +                uint32_t media_rate =
> (uint32_t)(sc->elst_data[i].rate * 65536.0);
> +                AV_WB64((elst_data+(i*20)), sc->elst_data[i].duration);
> +                AV_WB64((elst_data+(i*20)+8), sc->elst_data[i].time);
> +                AV_WB32((elst_data+(i*20)+16), media_rate);
> +            }
> +        }
> +    }
> +
>      /* Do not need those anymore. */
>      av_freep(&sc->chunk_offsets);
>      av_freep(&sc->sample_sizes);
> --
> 2.27.0