[FFmpeg-devel] [PATCH] ffprobe: allocate & free AVFrame per process_frame()

[Stefano Sabatini]

On date Tuesday 2013-12-24 00:42:31 +0100, Michael Niedermayer encoded:
> Fixes memleak
> 
> Signed-off-by: Michael Niedermayer <michaelni at gmx.at>
> ---
>  ffprobe.c |   17 +++++++++--------
>  1 file changed, 9 insertions(+), 8 deletions(-)
> 
> diff --git a/ffprobe.c b/ffprobe.c
> index 2bb72ab..b675f8b 100644
> --- a/ffprobe.c
> +++ b/ffprobe.c
> @@ -1783,13 +1783,13 @@ static void show_frame(WriterContext *w, AVFrame *frame, AVStream *stream,
>  
>  static av_always_inline int process_frame(WriterContext *w,
>                                            AVFormatContext *fmt_ctx,
> -                                          AVFrame *frame, AVPacket *pkt)
> +                                          AVPacket *pkt)
>  {
>      AVCodecContext *dec_ctx = fmt_ctx->streams[pkt->stream_index]->codec;
>      AVSubtitle sub;
>      int ret = 0, got_frame = 0;
> +    AVFrame *frame = av_frame_alloc();
>  
> -    avcodec_get_frame_defaults(frame);
>      if (dec_ctx->codec) {
>          switch (dec_ctx->codec_type) {
>          case AVMEDIA_TYPE_VIDEO:
> @@ -1806,8 +1806,10 @@ static av_always_inline int process_frame(WriterContext *w,
>          }
>      }
>  
> -    if (ret < 0)
> +    if (ret < 0) {
> +        av_frame_free(&frame);
>          return ret;
> +    }
>      ret = FFMIN(ret, pkt->size); /* guard against bogus return values */
>      pkt->data += ret;
>      pkt->size -= ret;
> @@ -1822,6 +1824,8 @@ static av_always_inline int process_frame(WriterContext *w,
>          if (is_sub)
>              avsubtitle_free(&sub);
>      }
> +    av_frame_free(&frame);
> +
>      return got_frame;
>  }
>  
> @@ -1853,7 +1857,6 @@ static int read_interval_packets(WriterContext *w, AVFormatContext *fmt_ctx,
>                                   const ReadInterval *interval, int64_t *cur_ts)
>  {
>      AVPacket pkt, pkt1;
> -    AVFrame *frame = NULL;
>      int ret = 0, i = 0, frame_count = 0;
>      int64_t start = -INT64_MAX, end = interval->end;
>      int has_start = 0, has_end = interval->has_end && !interval->end_is_offset;
> @@ -1887,7 +1890,6 @@ static int read_interval_packets(WriterContext *w, AVFormatContext *fmt_ctx,
>          }
>      }
>  
> -    frame = av_frame_alloc();
>      while (!av_read_frame(fmt_ctx, &pkt)) {
>          if (selected_streams[pkt.stream_index]) {
>              AVRational tb = fmt_ctx->streams[pkt.stream_index]->time_base;
> @@ -1920,7 +1922,7 @@ static int read_interval_packets(WriterContext *w, AVFormatContext *fmt_ctx,
>              }
>              if (do_read_frames) {
>                  pkt1 = pkt;
> -                while (pkt1.size && process_frame(w, fmt_ctx, frame, &pkt1) > 0);
> +                while (pkt1.size && process_frame(w, fmt_ctx, &pkt1) > 0);
>              }
>          }
>          av_free_packet(&pkt);
> @@ -1932,11 +1934,10 @@ static int read_interval_packets(WriterContext *w, AVFormatContext *fmt_ctx,
>      for (i = 0; i < fmt_ctx->nb_streams; i++) {
>          pkt.stream_index = i;
>          if (do_read_frames)
> -            while (process_frame(w, fmt_ctx, frame, &pkt) > 0);
> +            while (process_frame(w, fmt_ctx, &pkt) > 0);
>      }
>  
>  end:
> -    av_frame_free(&frame);
>      if (ret < 0) {
>          av_log(NULL, AV_LOG_ERROR, "Could not read packets in interval ");
>          log_read_interval(interval, NULL, AV_LOG_ERROR);

Question: is the leak a regression, depending on the frame API dance?
If not, why didn't we spot it before?

The original intent of allocating the frame outside process_frame()
was to avoid unnecessary alloc/free calls, but if that it's now
required for some reasons then patch is fine.

Thanks.
-- 
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