[FFmpeg-devel] [PATCH v3 4/6] ffmpeg: pass decoded or filtered AVFrame to output stream initialization

[Anton Khirnov]

Quoting Jan Ekström (2020-10-16 15:16:47)
> Additionally, reap the first rewards by being able to set the
> color related encoding values based on the passed AVFrame.
> 
> The only tests that seem to have changed their results with this
> change seem to be the MXF tests. There, the muxer writes the
> limited/full range flag to the output container if the encoder
> is not set to "unspecified".
> ---
>  fftools/ffmpeg.c            | 42 +++++++++++++++++++++++++++----------
>  tests/ref/lavf/mxf_d10      |  2 +-
>  tests/ref/lavf/mxf_dv25     |  2 +-
>  tests/ref/lavf/mxf_dvcpro50 |  2 +-
>  tests/ref/lavf/mxf_opatom   |  2 +-
>  5 files changed, 35 insertions(+), 15 deletions(-)
> 
> diff --git a/fftools/ffmpeg.c b/fftools/ffmpeg.c
> index 08db67a6ab..b2e210c814 100644
> --- a/fftools/ffmpeg.c
> +++ b/fftools/ffmpeg.c
> @@ -941,9 +941,11 @@ early_exit:
>      return float_pts;
>  }
>  
> -static int init_output_stream(OutputStream *ost, char *error, int error_len);
> +static int init_output_stream(OutputStream *ost, AVFrame *frame,
> +                              char *error, int error_len);
>  
> -static int init_output_stream_wrapper(OutputStream *ost, unsigned int fatal)
> +static int init_output_stream_wrapper(OutputStream *ost, AVFrame *frame,
> +                                      unsigned int fatal)
>  {
>      int ret = AVERROR_BUG;
>      char error[1024] = {0};
> @@ -951,7 +953,7 @@ static int init_output_stream_wrapper(OutputStream *ost, unsigned int fatal)
>      if (ost->initialized)
>          return 0;
>  
> -    ret = init_output_stream(ost, error, sizeof(error));
> +    ret = init_output_stream(ost, frame, error, sizeof(error));
>      if (ret < 0) {
>          av_log(NULL, AV_LOG_ERROR, "Error initializing output stream %d:%d -- %s\n",
>                 ost->file_index, ost->index, error);
> @@ -1125,7 +1127,7 @@ static void do_video_out(OutputFile *of,
>      InputStream *ist = NULL;
>      AVFilterContext *filter = ost->filter->filter;
>  
> -    init_output_stream_wrapper(ost, 1);
> +    init_output_stream_wrapper(ost, next_picture, 1);
>      sync_ipts = adjust_frame_pts_to_encoder_tb(of, ost, next_picture);
>  
>      if (ost->source_index >= 0)
> @@ -1507,7 +1509,7 @@ static int reap_filters(int flush)
>           * the encoder earlier than receiving the first AVFrame.
>           */
>          if (av_buffersink_get_type(filter) == AVMEDIA_TYPE_AUDIO)
> -            init_output_stream_wrapper(ost, 1);
> +            init_output_stream_wrapper(ost, NULL, 1);
>  
>          if (!ost->filtered_frame && !(ost->filtered_frame = av_frame_alloc())) {
>              return AVERROR(ENOMEM);
> @@ -1930,7 +1932,7 @@ static void flush_encoders(void)
>                  finish_output_stream(ost);
>              }
>  
> -            init_output_stream_wrapper(ost, 1);
> +            init_output_stream_wrapper(ost, NULL, 1);
>          }
>  
>          if (enc->codec_type != AVMEDIA_TYPE_VIDEO && enc->codec_type != AVMEDIA_TYPE_AUDIO)
> @@ -3302,7 +3304,7 @@ static void init_encoder_time_base(OutputStream *ost, AVRational default_time_ba
>      enc_ctx->time_base = default_time_base;
>  }
>  
> -static int init_output_stream_encode(OutputStream *ost)
> +static int init_output_stream_encode(OutputStream *ost, AVFrame *frame)
>  {
>      InputStream *ist = get_input_stream(ost);
>      AVCodecContext *enc_ctx = ost->enc_ctx;
> @@ -3399,6 +3401,23 @@ static int init_output_stream_encode(OutputStream *ost)
>              enc_ctx->bits_per_raw_sample = FFMIN(dec_ctx->bits_per_raw_sample,
>                                                   av_pix_fmt_desc_get(enc_ctx->pix_fmt)->comp[0].depth);
>  
> +        if (frame) {
> +            if (!av_dict_get(ost->encoder_opts, "color_range", NULL, 0))

It doesn't seem to me the checks are needed, since encoder_opts are
applied AFTER this block, so they'd override whatever you set here
anyway.

Beyond that, looks very good.

-- 
Anton Khirnov