[FFmpeg-devel] [PATCH] avcodec/mpegaudiodec_template: skip first frame after seeking

[wm4]

On Fri, 17 Apr 2015 19:04:02 +0200
Michael Niedermayer <michaelni at gmx.at> wrote:

> This could be made optional if preferred
> ---
>  libavcodec/mpegaudiodec_template.c |    7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/libavcodec/mpegaudiodec_template.c b/libavcodec/mpegaudiodec_template.c
> index 2326a90..70c17a1 100644
> --- a/libavcodec/mpegaudiodec_template.c
> +++ b/libavcodec/mpegaudiodec_template.c
> @@ -87,6 +87,7 @@ typedef struct MPADecodeContext {
>      MPADSPContext mpadsp;
>      AVFloatDSPContext *fdsp;
>      AVFrame *frame;
> +    int flushed;
>  } MPADecodeContext;
>  
>  #define HEADER_SIZE 4
> @@ -1645,6 +1646,11 @@ static int mp_decode_frame(MPADecodeContext *s, OUT_INT **samples,
>          }
>      }
>  
> +    if (s->flushed) {
> +        s->avctx->internal->skip_samples = FFMAX(s->avctx->internal->skip_samples, s->frame->nb_samples);
> +        s->flushed = 0;
> +    }
> +
>      return nb_frames * 32 * sizeof(OUT_INT) * s->nb_channels;
>  }
>  
> @@ -1723,6 +1729,7 @@ static void mp_flush(MPADecodeContext *ctx)
>      memset(ctx->mdct_buf, 0, sizeof(ctx->mdct_buf));
>      ctx->last_buf_size = 0;
>      ctx->dither_state = 0;
> +    ctx->flushed = 1;
>  }
>  
>  static void flush(AVCodecContext *avctx)

Would this not break gapless audio if you seek back to the first frame
after being done decoding? (Consider usecases like infinite looping.)