[FFmpeg-devel] [PATCH v2 1/4] avformat: add av_program_copy()

[Gyan Doshi]

On 2023-02-09 04:25 pm, Gyan Doshi wrote:
> Helper to transfer programs from one muxing context to another.
Comments?

Regards,
Gyan

> ---
>   doc/APIchanges         |  3 ++
>   libavformat/avformat.c | 70 ++++++++++++++++++++++++++++++++++++++++++
>   libavformat/avformat.h | 14 +++++++++
>   libavformat/version.h  |  2 +-
>   4 files changed, 88 insertions(+), 1 deletion(-)
>
> diff --git a/doc/APIchanges b/doc/APIchanges
> index 6baf914760..4916d1abe8 100644
> --- a/doc/APIchanges
> +++ b/doc/APIchanges
> @@ -14,6 +14,9 @@ libavutil:     2021-04-27
>   
>   API changes, most recent first:
>   
> +2023-02-xx - xxxxxxxxxx - lavf 59.39.100 - avformat.h
> +  Add av_program_copy()
> +
>   2023-0x-xx - xxxxxxxxxx - lavc 59.63.100
>     Allow AV_CODEC_FLAG_COPY_OPAQUE to be used with decoders.
>   
> diff --git a/libavformat/avformat.c b/libavformat/avformat.c
> index 19c7219471..d3c8def170 100644
> --- a/libavformat/avformat.c
> +++ b/libavformat/avformat.c
> @@ -359,6 +359,76 @@ void av_program_add_stream_index(AVFormatContext *ac, int progid, unsigned idx)
>       }
>   }
>   
> +int av_program_copy(AVFormatContext *dst, AVFormatContext *src, int progid, int overwrite)
> +{
> +    AVProgram *src_prog = NULL;
> +    AVProgram *dst_prog = NULL;
> +    int i, j, ret;
> +    int idx = -1;
> +
> +    for (i = 0; i < src->nb_programs; i++)
> +        if (src->programs[i]->id == progid)
> +            src_prog = src->programs[i];
> +
> +    if (!src_prog) {
> +        av_log(src, AV_LOG_ERROR, "source program not found: id=0x%04x\n", progid);
> +        return AVERROR(EINVAL);
> +    }
> +
> +    for (i = 0; i < dst->nb_programs; i++) {
> +        if (dst->programs[i]->id == progid)
> +            idx = i;
> +    }
> +
> +    if (idx >= 0 && !overwrite) {
> +        av_log(src, AV_LOG_ERROR, "target muxer already has program with id=0x%04x; not overwriting\n", progid);
> +        return AVERROR(EINVAL);
> +    }
> +
> +    av_log(src, AV_LOG_TRACE, "%s program: id=0x%04x\n", idx >= 0 ? "overwriting" : "copying", progid);
> +
> +    if (idx >= 0) {
> +        dst_prog = dst->programs[idx];
> +        av_dict_free(&dst_prog->metadata);
> +        av_freep(&dst_prog->stream_index);
> +        dst_prog->nb_stream_indexes = 0;
> +    } else {
> +        dst_prog = av_mallocz(sizeof(*dst_prog));
> +        if (!dst_prog)
> +            return AVERROR(ENOMEM);
> +        ret = av_dynarray_add_nofree(&dst->programs, &dst->nb_programs, dst_prog);
> +        if (ret < 0) {
> +            av_free(dst_prog);
> +            return AVERROR(ENOMEM);
> +        }
> +    }
> +
> +    /* public fields */
> +    dst_prog->id          = src_prog->id;
> +    dst_prog->flags       = src_prog->flags;
> +    dst_prog->discard     = src_prog->discard;
> +    dst_prog->program_num = src_prog->program_num;
> +    dst_prog->pmt_pid     = src_prog->pmt_pid;
> +    dst_prog->pcr_pid     = src_prog->pcr_pid;
> +    dst_prog->pmt_version = src_prog->pmt_version;
> +
> +    for (i = 0; i < dst->nb_streams; i++) {
> +        for (j = 0; j < src_prog->nb_stream_indexes; j++)
> +            if (dst->streams[i]->id == src->streams[src_prog->stream_index[j]]->id)
> +                av_program_add_stream_index(dst, dst_prog->id, i);
> +    }
> +
> +    av_dict_copy(&dst_prog->metadata, src_prog->metadata, 0);
> +
> +    /* private fields */
> +    dst_prog->start_time         = src_prog->start_time;
> +    dst_prog->end_time           = src_prog->end_time;
> +    dst_prog->pts_wrap_reference = src_prog->pts_wrap_reference;
> +    dst_prog->pts_wrap_behavior  = src_prog->pts_wrap_behavior;
> +
> +    return 0;
> +}
> +
>   AVProgram *av_find_program_from_stream(AVFormatContext *ic, AVProgram *last, int s)
>   {
>       for (unsigned i = 0; i < ic->nb_programs; i++) {
> diff --git a/libavformat/avformat.h b/libavformat/avformat.h
> index 1d97d56ac5..2b7ed3abd8 100644
> --- a/libavformat/avformat.h
> +++ b/libavformat/avformat.h
> @@ -1996,6 +1996,20 @@ uint8_t *av_stream_get_side_data(const AVStream *stream,
>   
>   AVProgram *av_new_program(AVFormatContext *s, int id);
>   
> +/**
> + * Copy an AVProgram from one AVFormatContext to another.
> + *
> + * @param dst           pointer to the target muxer context
> + * @param src           pointer to the source muxer context
> + * @param progid        ID of the program to be copied
> + * @param overwrite     whether to overwrite if target muxer already
> + *                      contains a program with the same ID
> + *
> + * @return  0 in case of success, a negative AVERROR code in case of
> + *          failure
> + */
> +int av_program_copy(AVFormatContext *dst, AVFormatContext *src, int progid, int overwrite);
> +
>   /**
>    * @}
>    */
> diff --git a/libavformat/version.h b/libavformat/version.h
> index 134cdb2b89..9aba356e09 100644
> --- a/libavformat/version.h
> +++ b/libavformat/version.h
> @@ -31,7 +31,7 @@
>   
>   #include "version_major.h"
>   
> -#define LIBAVFORMAT_VERSION_MINOR  38
> +#define LIBAVFORMAT_VERSION_MINOR  39
>   #define LIBAVFORMAT_VERSION_MICRO 100
>   
>   #define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \