Re: [FFmpeg-devel] [PATCH v7 1/2] avformat: refactor ff_stream_encode_params_copy() to stream_params_copy()

[Pierre-Anthony Lemieux <pal@sandflow.com>]

On Tue, Aug 9, 2022 at 6:05 PM Pierre-Anthony Lemieux <pal@sandflow.com> wrote:
>
> On Mon, Aug 8, 2022 at 7:50 AM Pierre-Anthony Lemieux <pal@sandflow.com> wrote:
> >
> > On Mon, Aug 8, 2022 at 7:48 AM Andreas Rheinhardt
> > <andreas.rheinhardt@outlook.com> wrote:
> > >
> > > pal@sandflow.com:
> > > > From: Pierre-Anthony Lemieux <pal@palemieux.com>
> > > >
> > > > Addresses http://ffmpeg.org/pipermail/ffmpeg-devel/2022-August/299726.html
> > > >
> > > > ---
> > > >  libavformat/avformat.c   | 66 ++++++++++++++++++++++++++++++++++++++++
> > > >  libavformat/fifo.c       |  8 ++---
> > > >  libavformat/internal.h   | 11 +++++++
> > > >  libavformat/mux.h        |  9 ------
> > > >  libavformat/mux_utils.c  | 28 -----------------
> > > >  libavformat/segment.c    |  6 ++--
> > > >  libavformat/tee.c        |  7 ++---
> > > >  libavformat/webm_chunk.c |  6 ++--
> > > >  8 files changed, 86 insertions(+), 55 deletions(-)
> > > >
> > > > diff --git a/libavformat/avformat.c b/libavformat/avformat.c
> > > > index 30d6ea6a49..19c7219471 100644
> > > > --- a/libavformat/avformat.c
> > > > +++ b/libavformat/avformat.c
> > > > @@ -235,6 +235,72 @@ int ff_stream_side_data_copy(AVStream *dst, const AVStream *src)
> > > >      return 0;
> > > >  }
> > > >
> > > > +/**
> > > > + * Copy all stream parameters from source to destination stream, with the
> > > > + * exception of the index field, which is usually set by avformat_new_stream().
> > > > + *
> > > > + * @param dst pointer to destination AVStream
> > > > + * @param src pointer to source AVStream
> > > > + * @return >=0 on success, AVERROR code on error
> > > > + */
> > > > +static int stream_params_copy(AVStream *dst, const AVStream *src)
> > > > +{
> > > > +    int ret;
> > > > +
> > > > +    dst->id                  = src->id;
> > > > +    dst->time_base           = src->time_base;
> > > > +    dst->start_time          = src->start_time;
> > > > +    dst->duration            = src->duration;
> > > > +    dst->nb_frames           = src->nb_frames;
> > > > +    dst->disposition         = src->disposition;
> > > > +    dst->discard             = src->discard;
> > > > +    dst->sample_aspect_ratio = src->sample_aspect_ratio;
> > > > +    dst->avg_frame_rate      = src->avg_frame_rate;
> > > > +    dst->event_flags         = src->event_flags;
> > > > +    dst->r_frame_rate        = src->r_frame_rate;
> > > > +    dst->pts_wrap_bits       = src->pts_wrap_bits;
> > > > +
> > > > +    av_dict_free(&dst->metadata);
> > > > +    ret = av_dict_copy(&dst->metadata, src->metadata, 0);
> > > > +    if (ret < 0)
> > > > +        return ret;
> > > > +
> > > > +    ret = avcodec_parameters_copy(dst->codecpar, src->codecpar);
> > > > +    if (ret < 0)
> > > > +        return ret;
> > > > +
> > > > +    ret = ff_stream_side_data_copy(dst, src);
> > > > +    if (ret < 0)
> > > > +        return ret;
> > > > +
> > > > +    av_packet_unref(&dst->attached_pic);
> > > > +    if (src->attached_pic.data) {
> > > > +        ret = av_packet_ref(&dst->attached_pic, &src->attached_pic);
> > > > +        if (ret < 0)
> > > > +            return ret;
> > > > +    }
> > > > +
> > > > +    return 0;
> > > > +}
> > > > +
> > > > +AVStream *ff_stream_clone(AVFormatContext *dst_ctx, const AVStream *src)
> > > > +{
> > > > +    AVStream *st;
> > > > +    int ret;
> > > > +
> > > > +    st = avformat_new_stream(dst_ctx, NULL);
> > > > +    if (!st)
> > > > +        return NULL;
> > > > +
> > > > +    ret = stream_params_copy(st, src);
> > > > +    if (ret < 0) {
> > > > +        ff_remove_stream(dst_ctx, st);
> > > > +        return NULL;
> > > > +    }
> > > > +
> > > > +    return st;
> > > > +}
> > > > +
> > > >  AVProgram *av_new_program(AVFormatContext *ac, int id)
> > > >  {
> > > >      AVProgram *program = NULL;
> > > > diff --git a/libavformat/fifo.c b/libavformat/fifo.c
> > > > index ead2bdc5cf..55d413b952 100644
> > > > --- a/libavformat/fifo.c
> > > > +++ b/libavformat/fifo.c
> > > > @@ -505,13 +505,11 @@ static int fifo_mux_init(AVFormatContext *avf, const AVOutputFormat *oformat,
> > > >      avf2->flags = avf->flags;
> > > >
> > > >      for (i = 0; i < avf->nb_streams; ++i) {
> > > > -        AVStream *st = avformat_new_stream(avf2, NULL);
> > > > +        AVStream *st = NULL;
> > > > +
> > > > +        st = ff_stream_clone(avf2, avf->streams[i]);
> > >
> > > I don't know why you stopped initializing st directly with its eventual
> > > value (if I see this corrently, the line wouldn't be overlong). I can
> > > fix this upon commit if you allow. Anyway, I will apply this in two days
> > > unless there are any comments from anyone else.
> >
> > I thought if(<assignment>) was not favored.
> >
> > Please modify as you see fit.
> >
> > Thanks.
>
> Couldn't this entire code block be simplified to the following?
>
>     for (i = 0; i < avf->nb_streams; ++i)
>         if (!ff_stream_clone(avf2, avf->streams[i]))
>             return AVERROR(ENOMEM);
>
> Happy to submit a revised patch if it helps.

See v8.

>
>
> >
> > >
> > > >          if (!st)
> > > >              return AVERROR(ENOMEM);
> > > > -
> > > > -        ret = ff_stream_encode_params_copy(st, avf->streams[i]);
> > > > -        if (ret < 0)
> > > > -            return ret;
> > > >      }
> > > >
> > > >      return 0;
> > > > diff --git a/libavformat/internal.h b/libavformat/internal.h
> > > > index b6b8fbf56f..9b07cfb271 100644
> > > > --- a/libavformat/internal.h
> > > > +++ b/libavformat/internal.h
> > > > @@ -625,6 +625,17 @@ enum AVCodecID ff_get_pcm_codec_id(int bps, int flt, int be, int sflags);
> > > >   */
> > > >  int ff_stream_side_data_copy(AVStream *dst, const AVStream *src);
> > > >
> > > > +/**
> > > > + * Create a new stream and copy to it all parameters from a source stream, with
> > > > + * the exception of the index field, which is set when the new stream is
> > > > + * created.
> > > > + *
> > > > + * @param dst_ctx pointer to the context in which the new stream is created
> > > > + * @param src pointer to source AVStream
> > > > + * @return pointer to the new stream or NULL on error
> > > > + */
> > > > +AVStream *ff_stream_clone(AVFormatContext *dst_ctx, const AVStream *src);
> > > > +
> > > >  /**
> > > >   * Wrap ffurl_move() and log if error happens.
> > > >   *
> > > > diff --git a/libavformat/mux.h b/libavformat/mux.h
> > > > index c01da82194..1bfcaf795f 100644
> > > > --- a/libavformat/mux.h
> > > > +++ b/libavformat/mux.h
> > > > @@ -113,15 +113,6 @@ int ff_format_shift_data(AVFormatContext *s, int64_t read_start, int shift_size)
> > > >   */
> > > >  int ff_format_output_open(AVFormatContext *s, const char *url, AVDictionary **options);
> > > >
> > > > -/**
> > > > - * Copy encoding parameters from source to destination stream
> > > > - *
> > > > - * @param dst pointer to destination AVStream
> > > > - * @param src pointer to source AVStream
> > > > - * @return >=0 on success, AVERROR code on error
> > > > - */
> > > > -int ff_stream_encode_params_copy(AVStream *dst, const AVStream *src);
> > > > -
> > > >  /**
> > > >   * Parse creation_time in AVFormatContext metadata if exists and warn if the
> > > >   * parsing fails.
> > > > diff --git a/libavformat/mux_utils.c b/libavformat/mux_utils.c
> > > > index eb8ea3d560..2fa2ab5b0f 100644
> > > > --- a/libavformat/mux_utils.c
> > > > +++ b/libavformat/mux_utils.c
> > > > @@ -121,34 +121,6 @@ int ff_format_output_open(AVFormatContext *s, const char *url, AVDictionary **op
> > > >      return 0;
> > > >  }
> > > >
> > > > -int ff_stream_encode_params_copy(AVStream *dst, const AVStream *src)
> > > > -{
> > > > -    int ret;
> > > > -
> > > > -    dst->id                  = src->id;
> > > > -    dst->time_base           = src->time_base;
> > > > -    dst->nb_frames           = src->nb_frames;
> > > > -    dst->disposition         = src->disposition;
> > > > -    dst->sample_aspect_ratio = src->sample_aspect_ratio;
> > > > -    dst->avg_frame_rate      = src->avg_frame_rate;
> > > > -    dst->r_frame_rate        = src->r_frame_rate;
> > > > -
> > > > -    av_dict_free(&dst->metadata);
> > > > -    ret = av_dict_copy(&dst->metadata, src->metadata, 0);
> > > > -    if (ret < 0)
> > > > -        return ret;
> > > > -
> > > > -    ret = avcodec_parameters_copy(dst->codecpar, src->codecpar);
> > > > -    if (ret < 0)
> > > > -        return ret;
> > > > -
> > > > -    ret = ff_stream_side_data_copy(dst, src);
> > > > -    if (ret < 0)
> > > > -        return ret;
> > > > -
> > > > -    return 0;
> > > > -}
> > > > -
> > > >  int ff_parse_creation_time_metadata(AVFormatContext *s, int64_t *timestamp, int return_seconds)
> > > >  {
> > > >      AVDictionaryEntry *entry;
> > > > diff --git a/libavformat/segment.c b/libavformat/segment.c
> > > > index fa435d9f32..c904e20708 100644
> > > > --- a/libavformat/segment.c
> > > > +++ b/libavformat/segment.c
> > > > @@ -167,11 +167,9 @@ static int segment_mux_init(AVFormatContext *s)
> > > >          AVStream *st, *ist = s->streams[i];
> > > >          AVCodecParameters *ipar = ist->codecpar, *opar;
> > > >
> > > > -        if (!(st = avformat_new_stream(oc, NULL)))
> > > > +        st = ff_stream_clone(oc, ist);
> > > > +        if (!st)
> > > >              return AVERROR(ENOMEM);
> > > > -        ret = ff_stream_encode_params_copy(st, ist);
> > > > -        if (ret < 0)
> > > > -            return ret;
> > > >          opar = st->codecpar;
> > > >          if (!oc->oformat->codec_tag ||
> > > >              av_codec_get_id (oc->oformat->codec_tag, ipar->codec_tag) == opar->codec_id ||
> > > > diff --git a/libavformat/tee.c b/libavformat/tee.c
> > > > index f1f2a9d2a5..dd408dd096 100644
> > > > --- a/libavformat/tee.c
> > > > +++ b/libavformat/tee.c
> > > > @@ -284,14 +284,11 @@ static int open_slave(AVFormatContext *avf, char *slave, TeeSlave *tee_slave)
> > > >          }
> > > >          tee_slave->stream_map[i] = stream_count++;
> > > >
> > > > -        if (!(st2 = avformat_new_stream(avf2, NULL))) {
> > > > +        st2 = ff_stream_clone(avf2, st);
> > > > +        if (!st2) {
> > > >              ret = AVERROR(ENOMEM);
> > > >              goto end;
> > > >          }
> > > > -
> > > > -        ret = ff_stream_encode_params_copy(st2, st);
> > > > -        if (ret < 0)
> > > > -            goto end;
> > > >      }
> > > >
> > > >      ret = ff_format_output_open(avf2, filename, &options);
> > > > diff --git a/libavformat/webm_chunk.c b/libavformat/webm_chunk.c
> > > > index d69db3a004..9e71a1209d 100644
> > > > --- a/libavformat/webm_chunk.c
> > > > +++ b/libavformat/webm_chunk.c
> > > > @@ -91,12 +91,10 @@ static int webm_chunk_init(AVFormatContext *s)
> > > >      if ((ret = av_dict_copy(&oc->metadata, s->metadata, 0)) < 0)
> > > >          return ret;
> > > >
> > > > -    if (!(st = avformat_new_stream(oc, NULL)))
> > > > +    st = ff_stream_clone(oc, ost);
> > > > +    if (!st)
> > > >          return AVERROR(ENOMEM);
> > > >
> > > > -    if ((ret = ff_stream_encode_params_copy(st, ost)) < 0)
> > > > -        return ret;
> > > > -
> > > >      if (wc->http_method)
> > > >          if ((ret = av_dict_set(&dict, "method", wc->http_method, 0)) < 0)
> > > >              return ret;
> > >
> > > _______________________________________________
> > > ffmpeg-devel mailing list
> > > ffmpeg-devel@ffmpeg.org
> > > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> > >
> > > To unsubscribe, visit link above, or email
> > > ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
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