[FFmpeg-devel] [PATCH 1/4] lavfi: parsing helper for unknown channel layouts.

[Stefano Sabatini]

On date Friday 2013-10-25 16:20:55 +0200, Nicolas George encoded:
> Make ff_parse_channel_layout() accept unknown layouts too.
> 
> Signed-off-by: Nicolas George <george at nsup.org>
> ---
>  libavfilter/af_aconvert.c   |  2 +-
>  libavfilter/af_pan.c        |  2 +-
>  libavfilter/asrc_aevalsrc.c |  2 +-
>  libavfilter/asrc_anullsrc.c |  2 +-
>  libavfilter/formats.c       | 17 +++++++++++++++--
>  libavfilter/internal.h      |  5 ++++-
>  6 files changed, 23 insertions(+), 7 deletions(-)
> 
> 
> At some point, some cleanup will probably be necessary amongst these various
> functions that do almost the same thing.
> Unfortunately, I believe there are plans to break everything on the fork.
> 
> 
> diff --git a/libavfilter/af_aconvert.c b/libavfilter/af_aconvert.c
> index a198d2b..43158f0 100644
> --- a/libavfilter/af_aconvert.c
> +++ b/libavfilter/af_aconvert.c
> @@ -66,7 +66,7 @@ static av_cold int init(AVFilterContext *ctx)
>          (ret = ff_parse_sample_format(&aconvert->out_sample_fmt, aconvert->format_str, ctx)) < 0)
>          return ret;
>      if (aconvert->channel_layout_str && strcmp(aconvert->channel_layout_str, "auto"))
> -        return ff_parse_channel_layout(&aconvert->out_chlayout, aconvert->channel_layout_str, ctx);
> +        return ff_parse_channel_layout(&aconvert->out_chlayout, NULL, aconvert->channel_layout_str, ctx);
>      return ret;
>  }
>  
> diff --git a/libavfilter/af_pan.c b/libavfilter/af_pan.c
> index 9cee9d9..e742d9e 100644
> --- a/libavfilter/af_pan.c
> +++ b/libavfilter/af_pan.c
> @@ -116,7 +116,7 @@ static av_cold int init(AVFilterContext *ctx)
>      if (!args)
>          return AVERROR(ENOMEM);
>      arg = av_strtok(args, "|", &tokenizer);
> -    ret = ff_parse_channel_layout(&pan->out_channel_layout, arg, ctx);
> +    ret = ff_parse_channel_layout(&pan->out_channel_layout, NULL, arg, ctx);
>      if (ret < 0)
>          goto fail;
>      pan->nb_output_channels = av_get_channel_layout_nb_channels(pan->out_channel_layout);
> diff --git a/libavfilter/asrc_aevalsrc.c b/libavfilter/asrc_aevalsrc.c
> index 3f71ac3..79fb4b2 100644
> --- a/libavfilter/asrc_aevalsrc.c
> +++ b/libavfilter/asrc_aevalsrc.c
> @@ -109,7 +109,7 @@ static av_cold int init(AVFilterContext *ctx)
>  
>      if (eval->chlayout_str) {
>          int n;
> -        ret = ff_parse_channel_layout(&eval->chlayout, eval->chlayout_str, ctx);
> +        ret = ff_parse_channel_layout(&eval->chlayout, NULL, eval->chlayout_str, ctx);
>          if (ret < 0)
>              goto end;
>  
> diff --git a/libavfilter/asrc_anullsrc.c b/libavfilter/asrc_anullsrc.c
> index 4f76759..a4bf013 100644
> --- a/libavfilter/asrc_anullsrc.c
> +++ b/libavfilter/asrc_anullsrc.c
> @@ -68,7 +68,7 @@ static av_cold int init(AVFilterContext *ctx)
>                                       null->sample_rate_str, ctx)) < 0)
>          return ret;
>  
> -    if ((ret = ff_parse_channel_layout(&null->channel_layout,
> +    if ((ret = ff_parse_channel_layout(&null->channel_layout, NULL,
>                                          null->channel_layout_str, ctx)) < 0)
>          return ret;
>  
> diff --git a/libavfilter/formats.c b/libavfilter/formats.c
> index d51bf3c..5816032 100644
> --- a/libavfilter/formats.c
> +++ b/libavfilter/formats.c
> @@ -615,10 +615,21 @@ int ff_parse_sample_rate(int *ret, const char *arg, void *log_ctx)
>      return 0;
>  }
>  
> -int ff_parse_channel_layout(int64_t *ret, const char *arg, void *log_ctx)
> +int ff_parse_channel_layout(int64_t *ret, int *nret, const char *arg,
> +                            void *log_ctx)
>  {
>      char *tail;
> -    int64_t chlayout = av_get_channel_layout(arg);
> +    int64_t chlayout, count;
> +
> +    if (nret) {
> +        count = strtol(arg, &tail, 10);
> +        if (*tail == 'c' && !tail[1] && count > 0 && count < 63) {
> +            *nret = count;
> +            *ret = 0;
> +            return 0;
> +        }
> +    }
> +    chlayout = av_get_channel_layout(arg);

what about another variant of av_get_channel_layout()?

>      if (chlayout == 0) {
>          chlayout = strtol(arg, &tail, 10);
>          if (*tail || chlayout == 0) {
> @@ -627,6 +638,8 @@ int ff_parse_channel_layout(int64_t *ret, const char *arg, void *log_ctx)
>          }
>      }
>      *ret = chlayout;
> +    if (nret)
> +        *nret = av_get_channel_layout_nb_channels(chlayout);
>      return 0;
>  }
>  
> diff --git a/libavfilter/internal.h b/libavfilter/internal.h
> index f8d0cce..0cb3c35 100644
> --- a/libavfilter/internal.h
> +++ b/libavfilter/internal.h
> @@ -207,11 +207,14 @@ int ff_parse_sample_format(int *ret, const char *arg, void *log_ctx);
>   * Parse a channel layout or a corresponding integer representation.
>   *
>   * @param ret 64bit integer pointer to where the value should be written.

> + * @param ret integer pointer to the number of channels;

nret

> + *            if not NULL, then unknown channel layouts are accepted
>   * @param arg string to parse
>   * @param log_ctx log context
>   * @return >= 0 in case of success, a negative AVERROR code on error
>   */
> -int ff_parse_channel_layout(int64_t *ret, const char *arg, void *log_ctx);
> +int ff_parse_channel_layout(int64_t *ret, int *nret, const char *arg,
> +                            void *log_ctx);
>  
>  void ff_update_link_current_pts(AVFilterLink *link, int64_t pts);

LGTM otherwise if useful for the following patches (which I still need
to read).
-- 
FFmpeg = Fanciful Fast Meaningless Purposeless Entertaining Gargoyle