[FFmpeg-devel] [PATCH v2] lavc/videotoolboxenc: Workaround encoder error

[Richard Kern]

> On Mar 24, 2016, at 1:56 PM, Rick Kern <kernrj at gmail.com> wrote:
> 
> CMVideoFormatDescriptionGetH264ParameterSetAtIndex() fails on some hardware/OS versions when retrieving the parameter set count alone.
> 
> Signed-off-by: Rick Kern <kernrj at gmail.com>
> ---
> libavcodec/videotoolboxenc.c | 43 ++++++++++++++++++++++++++++++++-----------
> 1 file changed, 32 insertions(+), 11 deletions(-)
> 
> diff --git a/libavcodec/videotoolboxenc.c b/libavcodec/videotoolboxenc.c
> index 0791146..3177074 100644
> --- a/libavcodec/videotoolboxenc.c
> +++ b/libavcodec/videotoolboxenc.c
> @@ -194,6 +194,7 @@ static int get_params_size(
> {
>     size_t total_size = 0;
>     size_t ps_count;
> +    int is_count_bad = 0;
>     size_t i;
>     int status;
>     status = CMVideoFormatDescriptionGetH264ParameterSetAtIndex(vid_fmt,
> @@ -203,11 +204,12 @@ static int get_params_size(
>                                                                 &ps_count,
>                                                                 NULL);
>     if (status) {
> -        av_log(avctx, AV_LOG_ERROR, "Error getting parameter set count: %d\n", status);
> -        return AVERROR_EXTERNAL;
> +        is_count_bad = 1;
> +        ps_count     = 0;
> +        status       = 0;
>     }
> 
> -    for(i = 0; i < ps_count; i++){
> +    for (i = 0; i < ps_count || is_count_bad; i++) {
>         const uint8_t *ps;
>         size_t ps_size;
>         status = CMVideoFormatDescriptionGetH264ParameterSetAtIndex(vid_fmt,
> @@ -216,14 +218,24 @@ static int get_params_size(
>                                                                     &ps_size,
>                                                                     NULL,
>                                                                     NULL);
> -        if(status){
> -            av_log(avctx, AV_LOG_ERROR, "Error getting parameter set size for index %zd: %d\n", i, status);
> -            return AVERROR_EXTERNAL;
> +        if (status) {
> +            /*
> +             * When ps_count is invalid, status != 0 ends the loop normally
> +             * unless we didn't get any parameter sets.
> +             */
> +            if (i > 0 && is_count_bad) status = 0;
> +
> +            break;
>         }
> 
>         total_size += ps_size + sizeof(start_code);
>     }
> 
> +    if (status) {
> +        av_log(avctx, AV_LOG_ERROR, "Error getting parameter set sizes: %d\n", status);
> +        return AVERROR_EXTERNAL;
> +    }
> +
>     *size = total_size;
>     return 0;
> }
> @@ -235,6 +247,7 @@ static int copy_param_sets(
>     size_t                      dst_size)
> {
>     size_t ps_count;
> +    int is_count_bad = 0;
>     int status;
>     size_t offset = 0;
>     size_t i;
> @@ -246,11 +259,13 @@ static int copy_param_sets(
>                                                                 &ps_count,
>                                                                 NULL);
>     if (status) {
> -        av_log(avctx, AV_LOG_ERROR, "Error getting parameter set count for copying: %d\n", status);
> -        return AVERROR_EXTERNAL;
> +        is_count_bad = 1;
> +        ps_count     = 0;
> +        status       = 0;
>     }
> 
> -    for (i = 0; i < ps_count; i++) {
> +
> +    for (i = 0; i < ps_count || is_count_bad; i++) {
>         const uint8_t *ps;
>         size_t ps_size;
>         size_t next_offset;
> @@ -262,8 +277,9 @@ static int copy_param_sets(
>                                                                     NULL,
>                                                                     NULL);
>         if (status) {
> -            av_log(avctx, AV_LOG_ERROR, "Error getting parameter set data for index %zd: %d\n", i, status);
> -            return AVERROR_EXTERNAL;
> +            if (i > 0 && is_count_bad) status = 0;
> +
> +            break;
>         }
> 
>         next_offset = offset + sizeof(start_code) + ps_size;
> @@ -279,6 +295,11 @@ static int copy_param_sets(
>         offset = next_offset;
>     }
> 
> +    if (status) {
> +        av_log(avctx, AV_LOG_ERROR, "Error getting parameter set data: %d\n", status);
> +        return AVERROR_EXTERNAL;
> +    }
> +
>     return 0;
> }
> 
> -- 
> 2.7.4
> 
Ping - does anyone else want to review? The logic is clearer and the commit message is better.