[FFmpeg-devel] [PATCH] avcodec_copy_context()

[Benoit Fouet]

Hi,

On Tue, 30 Mar 2010 14:23:03 -0400 Ronald S. Bultje wrote:
> Index: ffmpeg-svn/libavcodec/options.c
> ===================================================================
> --- ffmpeg-svn.orig/libavcodec/options.c	2010-03-29 13:37:31.000000000 -0400
> +++ ffmpeg-svn/libavcodec/options.c	2010-03-29 13:37:49.000000000 -0400
> @@ -471,3 +471,55 @@
>      return avcodec_alloc_context2(CODEC_TYPE_UNKNOWN);
>  }
>  
> +int avcodec_copy_context(AVCodecContext *dest, const AVCodecContext *src)
> +{
> +    memcpy(dest, src, sizeof(*dest));
> +
> +    /* set values specific to opened codecs back to their default state */
> +    dest->priv_data       = NULL;
> +    dest->codec           = NULL;
> +    dest->palctrl         = NULL;
> +    dest->slice_offset    = NULL;
> +    dest->internal_buffer = NULL;
> +    dest->hwaccel         = NULL;
> +    dest->execute         = NULL;
> +    dest->execute2        = NULL;
> +    dest->reget_buffer    = NULL;
> +    dest->thread_opaque   = NULL;

I'd add all the ones below, that you are going to override, in this
initialization list, that will ease your pain in case of error (see
below).

> +
> +    /* reallocate values that should be allocated separately */
> +    if (dest->rc_eq) {

Just for consistency, this should be testing src->rc_eq.

> +        dest->rc_eq = av_strdup(src->rc_eq);
> +        if (!dest->rc_eq)
> +            return AVERROR(ENOMEM);
> +    }
> +    if (src->extradata && src->extradata_size > 0) {
> +        dest->extradata = av_malloc(src->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
> +        if (!dest->extradata)
> +            return AVERROR(ENOMEM);

This is leaking rc_eq; and all the other 'return AVERROR(ENOMEM)' are
leaking something more. You should consider using a goto, or add a
function for cleaning purpose.

Ben