[FFmpeg-devel] [PATCH v3] avcodec/v4l2_m2m_enc: Check encoder pix_fmt matches pix_fmt on device

[Mark Thompson]

On 27/12/2019 23:38, Andriy Gelman wrote:
> From: Andriy Gelman <andriy.gelman at gmail.com>
> 
> Fixes #8079
> 
> During initialization of a v4l2m2m device, the configured pix_fmt can be
> different to the pix_fmt of the encoder (i.e. avctx->pix_fmt).
> 
> For example on the Odroid XU4:
> ./ffmpeg -f lavfi -i yuvtestsrc -codec:v h264_v4l2m2m out.h264
> 
> will configure the v4l2 encoder to pix_fmt nv21, whereas the input
> frames will be yuv444p.
> 
> This commit checks that the configured v4l2 pix_fmt on device is the
> same as avctx->pix_fmt. If they are different the initialization fails
> and an error is returned. Tested on RPI4 and Odroid XU4.
> 
> Signed-off-by: Andriy Gelman <andriy.gelman at gmail.com>
> ---
>  libavcodec/v4l2_m2m_enc.c | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)
> 
>  Changes in v3:
>     - Use main encoder context for logging instead of the private one
> 
> diff --git a/libavcodec/v4l2_m2m_enc.c b/libavcodec/v4l2_m2m_enc.c
> index 474e6bef897..8059e3bb48f 100644
> --- a/libavcodec/v4l2_m2m_enc.c
> +++ b/libavcodec/v4l2_m2m_enc.c
> @@ -30,6 +30,7 @@
>  #include "libavutil/opt.h"
>  #include "v4l2_context.h"
>  #include "v4l2_m2m.h"
> +#include "v4l2_fmt.h"
>  
>  #define MPEG_CID(x) V4L2_CID_MPEG_VIDEO_##x
>  #define MPEG_VIDEO(x) V4L2_MPEG_VIDEO_##x
> @@ -288,6 +289,8 @@ static av_cold int v4l2_encode_init(AVCodecContext *avctx)
>      V4L2Context *capture, *output;
>      V4L2m2mContext *s;
>      V4L2m2mPriv *priv = avctx->priv_data;
> +    enum AVPixelFormat pix_fmt_output;
> +    uint32_t v4l2_fmt_output;
>      int ret;
>  
>      ret = ff_v4l2_m2m_create_context(priv, &s);
> @@ -316,6 +319,18 @@ static av_cold int v4l2_encode_init(AVCodecContext *avctx)
>      }
>      s->avctx = avctx;
>  
> +    if (V4L2_TYPE_IS_MULTIPLANAR(output->type))
> +        v4l2_fmt_output = output->format.fmt.pix_mp.pixelformat;
> +    else
> +        v4l2_fmt_output = output->format.fmt.pix.pixelformat;
> +
> +    pix_fmt_output = ff_v4l2_format_v4l2_to_avfmt(v4l2_fmt_output, AV_CODEC_ID_RAWVIDEO);
> +    if (pix_fmt_output != avctx->pix_fmt) {
> +        const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt_output);
> +        av_log(avctx, AV_LOG_ERROR, "Encoder requires %s pixel format.\n", desc->name);
> +        return AVERROR(EINVAL);
> +    }
> +
>      return v4l2_prepare_encoder(s);
>  }
>  
> 

Yep, applied.

Thank you for your patience on this :/

- Mark