[FFmpeg-devel] [PATCH 2/3] avformat/mpc: Simplify cleanup

[Andreas Rheinhardt]

Andreas Rheinhardt:
> Currently Musepack allocates an array that needs to be freed later in
> the demuxer's read_close-function; it is the sole reason for said
> function's existence. But it is unnecessary, because one can store this
> array in the stream's priv_data pointer, so that it will be freed
> generically.
> 
> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>
> ---
>  libavformat/mpc.c | 40 ++++++++++++++++------------------------
>  1 file changed, 16 insertions(+), 24 deletions(-)
> 
> diff --git a/libavformat/mpc.c b/libavformat/mpc.c
> index 85036cd118..6a94b5d1d0 100644
> --- a/libavformat/mpc.c
> +++ b/libavformat/mpc.c
> @@ -57,6 +57,7 @@ static int mpc_read_header(AVFormatContext *s)
>  {
>      MPCContext *c = s->priv_data;
>      AVStream *st;
> +    int ret;
>  
>      if(avio_rl24(s->pb) != MKTAG('M', 'P', '+', 0)){
>          av_log(s, AV_LOG_ERROR, "Not a Musepack file\n");
> @@ -72,15 +73,6 @@ static int mpc_read_header(AVFormatContext *s)
>          av_log(s, AV_LOG_ERROR, "Too many frames, seeking is not possible\n");
>          return AVERROR_INVALIDDATA;
>      }
> -    if(c->fcount){
> -        c->frames = av_malloc(c->fcount * sizeof(MPCFrame));
> -        if(!c->frames){
> -            av_log(s, AV_LOG_ERROR, "Cannot allocate seektable\n");
> -            return AVERROR(ENOMEM);
> -        }
> -    }else{
> -        av_log(s, AV_LOG_WARNING, "Container reports no frames\n");
> -    }
>      c->curframe = 0;
>      c->lastframe = -1;
>      c->curbits = 8;
> @@ -88,15 +80,27 @@ static int mpc_read_header(AVFormatContext *s)
>  
>      st = avformat_new_stream(s, NULL);
>      if (!st)
> -        goto mem_error;
> +        return AVERROR(ENOMEM);
> +
> +    if (c->fcount) {
> +        c->frames = av_malloc(c->fcount * sizeof(MPCFrame));
> +        if (!c->frames) {
> +            av_log(s, AV_LOG_ERROR, "Cannot allocate seektable\n");
> +            return AVERROR(ENOMEM);
> +        }
> +        st->priv_data = c->frames;
> +    } else {
> +        av_log(s, AV_LOG_WARNING, "Container reports no frames\n");
> +    }
> +
>      st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
>      st->codecpar->codec_id = AV_CODEC_ID_MUSEPACK7;
>      st->codecpar->channels = 2;
>      st->codecpar->channel_layout = AV_CH_LAYOUT_STEREO;
>      st->codecpar->bits_per_coded_sample = 16;
>  
> -    if (ff_get_extradata(s, st->codecpar, s->pb, 16) < 0)
> -        goto mem_error;
> +    if ((ret = ff_get_extradata(s, st->codecpar, s->pb, 16)) < 0)
> +        return ret;
>      st->codecpar->sample_rate = mpc_rate[st->codecpar->extradata[2] & 3];
>      avpriv_set_pts_info(st, 32, MPC_FRAMESIZE, st->codecpar->sample_rate);
>      /* scan for seekpoints */
> @@ -113,9 +117,6 @@ static int mpc_read_header(AVFormatContext *s)
>      }
>  
>      return 0;
> -mem_error:
> -    av_freep(&c->frames);
> -    return AVERROR(ENOMEM);
>  }
>  
>  static int mpc_read_packet(AVFormatContext *s, AVPacket *pkt)
> @@ -176,14 +177,6 @@ static int mpc_read_packet(AVFormatContext *s, AVPacket *pkt)
>      return 0;
>  }
>  
> -static int mpc_read_close(AVFormatContext *s)
> -{
> -    MPCContext *c = s->priv_data;
> -
> -    av_freep(&c->frames);
> -    return 0;
> -}
> -
>  /**
>   * Seek to the given position
>   * If position is unknown but is within the limits of file
> @@ -232,7 +225,6 @@ AVInputFormat ff_mpc_demuxer = {
>      .read_probe     = mpc_probe,
>      .read_header    = mpc_read_header,
>      .read_packet    = mpc_read_packet,
> -    .read_close     = mpc_read_close,
>      .read_seek      = mpc_read_seek,
>      .extensions     = "mpc",
>  };
> 
Will push tomorrow if there are no objections.

- Andreas