Re: [FFmpeg-devel] [PATCH v5 1/2] avformat: refactor ff_stream_encode_params_copy() to ff_stream_params_copy()

[Andreas Rheinhardt <andreas.rheinhardt@outlook.com>]

pal@sandflow.com:
> From: Pierre-Anthony Lemieux <pal@palemieux.com>
> 
> As discussed at https://ffmpeg.org/pipermail/ffmpeg-devel/2022-July/298491.html.
> Note that ff_stream_params_copy() does not copy:
>  * the index field
>  * the attached_pic if its size is 0
> 
> Addresses http://ffmpeg.org/pipermail/ffmpeg-devel/2022-August/299514.html
> 
> ---
>  libavformat/avformat.c   | 40 ++++++++++++++++++++++++++++++++++++++++
>  libavformat/fifo.c       |  2 +-
>  libavformat/internal.h   | 12 ++++++++++++
>  libavformat/mux.h        |  9 ---------
>  libavformat/mux_utils.c  | 28 ----------------------------
>  libavformat/segment.c    |  2 +-
>  libavformat/tee.c        |  2 +-
>  libavformat/webm_chunk.c |  2 +-
>  8 files changed, 56 insertions(+), 41 deletions(-)
> 
> diff --git a/libavformat/avformat.c b/libavformat/avformat.c
> index 30d6ea6a49..242187c359 100644
> --- a/libavformat/avformat.c
> +++ b/libavformat/avformat.c
> @@ -235,6 +235,46 @@ int ff_stream_side_data_copy(AVStream *dst, const AVStream *src)
>      return 0;
>  }
>  
> +int ff_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.size > 0) {
> +        ret = av_packet_ref(&dst->attached_pic, &src->attached_pic);
> +        if (ret < 0)
> +            return ret;
> +    }
> +
> +    return 0;
> +}
> +
>  AVProgram *av_new_program(AVFormatContext *ac, int id)
>  {
>      AVProgram *program = NULL;
> diff --git a/libavformat/fifo.c b/libavformat/fifo.c
> index ead2bdc5cf..fef116d040 100644
> --- a/libavformat/fifo.c
> +++ b/libavformat/fifo.c
> @@ -509,7 +509,7 @@ static int fifo_mux_init(AVFormatContext *avf, const AVOutputFormat *oformat,
>          if (!st)
>              return AVERROR(ENOMEM);
>  
> -        ret = ff_stream_encode_params_copy(st, avf->streams[i]);
> +        ret = ff_stream_params_copy(st, avf->streams[i]);
>          if (ret < 0)
>              return ret;
>      }
> diff --git a/libavformat/internal.h b/libavformat/internal.h
> index b6b8fbf56f..87a00bbae3 100644
> --- a/libavformat/internal.h
> +++ b/libavformat/internal.h
> @@ -625,6 +625,18 @@ 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);
>  
> +/**
> + * Copy all stream parameters from source to destination stream, with the
> + * exception of:
> + *  * the index field, which is usually set by avformat_new_stream()
> + *  * the attached_pic field, if attached_pic.size is 0 or less
> + *
> + * @param dst pointer to destination AVStream
> + * @param src pointer to source AVStream
> + * @return >=0 on success, AVERROR code on error
> + */
> +int ff_stream_params_copy(AVStream *dst, 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..a8f3e94714 100644
> --- a/libavformat/segment.c
> +++ b/libavformat/segment.c
> @@ -169,7 +169,7 @@ static int segment_mux_init(AVFormatContext *s)
>  
>          if (!(st = avformat_new_stream(oc, NULL)))
>              return AVERROR(ENOMEM);
> -        ret = ff_stream_encode_params_copy(st, ist);
> +        ret = ff_stream_params_copy(st, ist);
>          if (ret < 0)
>              return ret;
>          opar = st->codecpar;
> diff --git a/libavformat/tee.c b/libavformat/tee.c
> index f1f2a9d2a5..dbfad604d0 100644
> --- a/libavformat/tee.c
> +++ b/libavformat/tee.c
> @@ -289,7 +289,7 @@ static int open_slave(AVFormatContext *avf, char *slave, TeeSlave *tee_slave)
>              goto end;
>          }
>  
> -        ret = ff_stream_encode_params_copy(st2, st);
> +        ret = ff_stream_params_copy(st2, st);
>          if (ret < 0)
>              goto end;
>      }
> diff --git a/libavformat/webm_chunk.c b/libavformat/webm_chunk.c
> index d69db3a004..39f21fce7a 100644
> --- a/libavformat/webm_chunk.c
> +++ b/libavformat/webm_chunk.c
> @@ -94,7 +94,7 @@ static int webm_chunk_init(AVFormatContext *s)
>      if (!(st = avformat_new_stream(oc, NULL)))
>          return AVERROR(ENOMEM);
>  
> -    if ((ret = ff_stream_encode_params_copy(st, ost)) < 0)
> +    if ((ret = ff_stream_params_copy(st, ost)) < 0)
>          return ret;
>  
>      if (wc->http_method)

Looking at these callers shows that they all have one thing in common:
They create a stream and immediately afterwards copy stream parameters.
The caller that you intend to add in #2 does the same. How about we make
a function that is equivalent to
avformat_new_stream+ff_stream_params_copy above and use that? (But
please leave ff_stream_params_copy as it is in the form of a static
function.)

- Andreas
_______________________________________________
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".