[FFmpeg-devel] [PATCH] swresample fixes

[James Almer]

On 1/4/2023 1:59 PM, Paul B Mahol wrote:
> From 0415ed37bee0c2b640920edad87ec927dda95fb5 Mon Sep 17 00:00:00 2001
> From: Paul B Mahol <onemda at gmail.com>
> Date: Wed, 4 Jan 2023 17:53:01 +0100
> Subject: [PATCH 2/3] swresample/swresample_frame: fix regression in detecting
>  changes
> 
> Do not overwrite return variable values, instead use different
> one for checking results.
> 
> Signed-off-by: Paul B Mahol <onemda at gmail.com>
> ---
>  libswresample/swresample_frame.c | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/libswresample/swresample_frame.c b/libswresample/swresample_frame.c
> index 53ac487136..319ce045a1 100644
> --- a/libswresample/swresample_frame.c
> +++ b/libswresample/swresample_frame.c
> @@ -84,7 +84,7 @@ static int config_changed(SwrContext *s,
>                            const AVFrame *out, const AVFrame *in)
>  {
>      AVChannelLayout ch_layout = { 0 };
> -    int ret = 0;
> +    int ret = 0, iret;
>  
>      if (in) {
>  #if FF_API_OLD_CHANNEL_LAYOUT
> @@ -96,8 +96,8 @@ FF_DISABLE_DEPRECATION_WARNINGS
>  FF_ENABLE_DEPRECATION_WARNINGS
>          } else
>  #endif
> -        if ((ret = av_channel_layout_copy(&ch_layout, &in->ch_layout)) < 0)
> -            return ret;
> +        if ((iret = av_channel_layout_copy(&ch_layout, &in->ch_layout)) < 0)
> +            return iret;
>          if (av_channel_layout_compare(&s->in_ch_layout, &ch_layout) ||
>              s->in_sample_rate != in->sample_rate ||
>              s->in_sample_fmt  != in->format) {
> @@ -116,8 +116,8 @@ FF_DISABLE_DEPRECATION_WARNINGS
>  FF_ENABLE_DEPRECATION_WARNINGS
>          } else
>  #endif
> -        if ((ret = av_channel_layout_copy(&ch_layout, &out->ch_layout)) < 0)
> -            return ret;
> +        if ((iret = av_channel_layout_copy(&ch_layout, &out->ch_layout)) < 0)
> +            return iret;
>          if (av_channel_layout_compare(&s->out_ch_layout, &ch_layout) ||
>              s->out_sample_rate != out->sample_rate ||
>              s->out_sample_fmt  != out->format) {

Patch 2/3 LGTM, and it should be backported to 5.1.

Also, FWIW, these copies will be unnecessary after the old channel 
layout API is dropped, so this can be undone later.