[FFmpeg-devel] [PATCH] ffmpeg/avformat: factor av_guess_frame_rate() out

[Stefano Sabatini]

On date Wednesday 2013-03-27 22:48:50 +0100, Michael Niedermayer encoded:
> This will be used in ffplay
> 
> Signed-off-by: Michael Niedermayer <michaelni at gmx.at>
> ---
>  ffmpeg_filter.c        |   13 +++----------
>  libavformat/avformat.h |   10 ++++++++++
>  libavformat/utils.c    |   16 ++++++++++++++++
>  3 files changed, 29 insertions(+), 10 deletions(-)

missing minor bump and APIchanges entry

> 
> diff --git a/ffmpeg_filter.c b/ffmpeg_filter.c
> index 654c19d..6824af6 100644
> --- a/ffmpeg_filter.c
> +++ b/ffmpeg_filter.c
> @@ -542,22 +542,15 @@ static int configure_input_video_filter(FilterGraph *fg, InputFilter *ifilter,
>      InputStream *ist = ifilter->ist;
>      AVRational tb = ist->framerate.num ? av_inv_q(ist->framerate) :
>                                           ist->st->time_base;
> -    AVRational fr = ist->framerate.num ? ist->framerate :
> -                                         ist->st->r_frame_rate;
> +    AVRational fr = ist->framerate;
>      AVRational sar;
>      AVBPrint args;
>      char name[255];
>      int pad_idx = in->pad_idx;
>      int ret;
>  
> -    if (!ist->framerate.num && ist->st->codec->ticks_per_frame>1) {
> -        AVRational codec_fr = av_inv_q(ist->st->codec->time_base);
 -        AVRational   avg_fr = ist->st->avg_frame_rate;
> -        codec_fr.den *= ist->st->codec->ticks_per_frame;
> -        if (   codec_fr.num>0 && codec_fr.den>0 && av_q2d(codec_fr) < av_q2d(fr)*0.7
> -            && fabs(1.0 - av_q2d(av_div_q(avg_fr, fr)))>0.1)
> -            fr = codec_fr;
> -    }
> +    if (!fr.num)
> +        fr = av_guess_frame_rate(input_files[ist->file_index]->ctx, ist->st, NULL);
>  
>      if (ist->st->codec->codec_type == AVMEDIA_TYPE_SUBTITLE) {
>          ret = sub2video_prepare(ist);
> diff --git a/libavformat/avformat.h b/libavformat/avformat.h
> index 549a0fa..9b3aeb0 100644
> --- a/libavformat/avformat.h
> +++ b/libavformat/avformat.h
> @@ -2108,6 +2108,16 @@ const struct AVCodecTag *avformat_get_riff_audio_tags(void);
>  AVRational av_guess_sample_aspect_ratio(AVFormatContext *format, AVStream *stream, AVFrame *frame);
>  

>  /**
> + * Guess the frame rate, based on both the container and codec information.
> + *
> + * @param format the format context which the stream is part of
> + * @param stream the stream which the frame is part of
> + * @param frame the frame for which the frame rate should be determined, may be NULL
> + * @return the guessed (valid) frame rate, 0/1 if no idea
> + */
> +AVRational av_guess_frame_rate(AVFormatContext *format, AVStream *stream, AVFrame *frame);

nit: format_ctx

> +
> +/**
>   * Check if the stream st contained in s is matched by the stream specifier
>   * spec.
>   *
> diff --git a/libavformat/utils.c b/libavformat/utils.c
> index f9acc0e..025cad3 100644
> --- a/libavformat/utils.c
> +++ b/libavformat/utils.c
> @@ -4276,6 +4276,22 @@ AVRational av_guess_sample_aspect_ratio(AVFormatContext *format, AVStream *strea
>          return frame_sample_aspect_ratio;
>  }
>  
> +AVRational av_guess_frame_rate(AVFormatContext *format, AVStream *st, AVFrame *frame)
> +{
> +    AVRational fr = st->r_frame_rate;
> +
> +    if (st->codec->ticks_per_frame>1) {
> +        AVRational codec_fr = av_inv_q(st->codec->time_base);
> +        AVRational   avg_fr = st->avg_frame_rate;
> +        codec_fr.den *= st->codec->ticks_per_frame;

> +        if (   codec_fr.num>0 && codec_fr.den>0 && av_q2d(codec_fr) < av_q2d(fr)*0.7
> +            && fabs(1.0 - av_q2d(av_div_q(avg_fr, fr)))>0.1)

A comment about the magick would be nice.

> +            fr = codec_fr;
> +    }
> +
> +    return fr;
> +}

LGTM otherwise, thanks.
-- 
FFmpeg = Foolish Fiendish MultiPurpose Erotic Gladiator