[FFmpeg-devel] [PATCH 2/2] lavf/mux: clarify log messages when choosing oformat fails

[Stefano Sabatini]

On date Thursday 2023-03-30 11:38:08 +0200, Anton Khirnov wrote:
> Current log messages talk about 'suitable' output formats. This is
> confusing, because it suggests that some formats are suitable, while
> others are not, which is not the case.
> 
> Also, suggest possible user actions when format cannot be guessed from a
> filename.
> ---
>  libavformat/mux.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/libavformat/mux.c b/libavformat/mux.c
> index 0bc9b6b87d..415bd3948f 100644
> --- a/libavformat/mux.c
> +++ b/libavformat/mux.c
> @@ -102,7 +102,7 @@ int avformat_alloc_output_context2(AVFormatContext **avctx, const AVOutputFormat
>          if (format) {
>              oformat = av_guess_format(format, NULL, NULL);
>              if (!oformat) {
> -                av_log(s, AV_LOG_ERROR, "Requested output format '%s' is not a suitable output format\n", format);
> +                av_log(s, AV_LOG_ERROR, "Requested output format '%s' is not known.\n", format);
>                  ret = AVERROR(EINVAL);
>                  goto error;
>              }
> @@ -110,8 +110,10 @@ int avformat_alloc_output_context2(AVFormatContext **avctx, const AVOutputFormat
>              oformat = av_guess_format(NULL, filename, NULL);
>              if (!oformat) {
>                  ret = AVERROR(EINVAL);
> -                av_log(s, AV_LOG_ERROR, "Unable to find a suitable output format for '%s'\n",
> -                       filename);
> +                av_log(s, AV_LOG_ERROR,
> +                       "Unable to choose an output format for '%s'; "
> +                       "use a standard extension for the filename or specify "
> +                       "the format manually.\n", filename);

LGTM.