[FFmpeg-devel] [PATCH] lavc/cuvid: fail early if GPU can't handle video parameters

Pavel Koshevoy pkoshevoy at gmail.com
Fri Jan 13 03:06:16 EET 2017


On 01/12/2017 10:32 AM, Timo Rothenpieler wrote:
> On 1/9/2017 7:22 PM, pkoshevoy at gmail.com wrote:
>> From: Pavel Koshevoy <pkoshevoy at gmail.com>
>>
>> Evidently CUVID doesn't support decoding 422 or 444 chroma formats,
>> and only a limited set of resolutions per codec are supported.
>>
>> Given that stream resolution and pixel format are typically known as a
>> result of probing it is better to use this info during avcodec_open2
>> call and fail early in case the video parameters are not supported,
>> rather than failing later during avcodec_send_packet calls.
>>
>> This problem surfaced when trying to decode 5120x2700 h246 video on
>> GeForce GT 730, or when decoding 422 mpeg2/h264 streams on same GPU -
>> avcodec_open2 succeeds but decoding fails.
>> ---
>>   libavcodec/cuvid.c | 62 +++++++++++++++++++++++++++++++++++++++++++++++++-----
>>   1 file changed, 57 insertions(+), 5 deletions(-)
>>
>> diff --git a/libavcodec/cuvid.c b/libavcodec/cuvid.c
>> index 8fc713d..ed21f94 100644
>> --- a/libavcodec/cuvid.c
>> +++ b/libavcodec/cuvid.c
>> @@ -612,7 +612,11 @@ static av_cold int cuvid_decode_end(AVCodecContext *avctx)
>>       return 0;
>>   }
>>   
>> -static int cuvid_test_dummy_decoder(AVCodecContext *avctx, CUVIDPARSERPARAMS *cuparseinfo)
>> +static int cuvid_test_dummy_decoder(AVCodecContext *avctx,
>> +                                    const CUVIDPARSERPARAMS *cuparseinfo,
>> +                                    cudaVideoChromaFormat probed_chroma_format,
>> +                                    int probed_width,
>> +                                    int probed_height)
>>   {
>>       CuvidContext *ctx = avctx->priv_data;
>>       CUVIDDECODECREATEINFO cuinfo;
>> @@ -622,11 +626,11 @@ static int cuvid_test_dummy_decoder(AVCodecContext *avctx, CUVIDPARSERPARAMS *cu
>>       memset(&cuinfo, 0, sizeof(cuinfo));
>>   
>>       cuinfo.CodecType = cuparseinfo->CodecType;
>> -    cuinfo.ChromaFormat = cudaVideoChromaFormat_420;
>> +    cuinfo.ChromaFormat = probed_chroma_format;
>>       cuinfo.OutputFormat = cudaVideoSurfaceFormat_NV12;
>>   
>> -    cuinfo.ulWidth = 1280;
>> -    cuinfo.ulHeight = 720;
>> +    cuinfo.ulWidth = probed_width;
>> +    cuinfo.ulHeight = probed_height;
>>       cuinfo.ulTargetWidth = cuinfo.ulWidth;
>>       cuinfo.ulTargetHeight = cuinfo.ulHeight;
>>   
>> @@ -653,6 +657,36 @@ static int cuvid_test_dummy_decoder(AVCodecContext *avctx, CUVIDPARSERPARAMS *cu
>>       return 0;
>>   }
>>   
>> +static int convert_to_cuda_video_chroma_format(enum AVPixelFormat pix_fmt,
>> +                                               cudaVideoChromaFormat *out)
>> +{
>> +    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
>> +    if (!(out && desc &&
>> +          (desc->nb_components == 1 || desc->nb_components == 3) &&
>> +          (desc->log2_chroma_w < 2 && desc->log2_chroma_h < 2)))
>> +    {
>> +        return AVERROR(EINVAL);
>> +    }
>> +
>> +    if (desc->nb_components == 1)
>> +    {
>> +        *out = cudaVideoChromaFormat_Monochrome;
>> +    }
>> +    else if (desc->flags == AV_PIX_FMT_FLAG_PLANAR)
>> +    {
>> +        *out = ((desc->log2_chroma_w == 0) ? cudaVideoChromaFormat_444 :
>> +                (desc->log2_chroma_h == 0) ? cudaVideoChromaFormat_422 :
>> +                cudaVideoChromaFormat_420);
>> +    }
>> +    else
>> +    {
>> +        return AVERROR(EINVAL);
>> +    }
>> +
>> +    // unfortunately, 420 is the only one that works:
>> +    return (*out == cudaVideoChromaFormat_420) ? 0 : AVERROR_EXTERNAL;
>> +}
>> +
>>   static av_cold int cuvid_decode_init(AVCodecContext *avctx)
>>   {
>>       CuvidContext *ctx = avctx->priv_data;
>> @@ -663,12 +697,27 @@ static av_cold int cuvid_decode_init(AVCodecContext *avctx)
>>       CUcontext cuda_ctx = NULL;
>>       CUcontext dummy;
>>       const AVBitStreamFilter *bsf;
>> +    cudaVideoChromaFormat probed_chroma_format;
>> +    int probed_width;
>> +    int probed_height;
>>       int ret = 0;
>>   
>>       enum AVPixelFormat pix_fmts[3] = { AV_PIX_FMT_CUDA,
>>                                          AV_PIX_FMT_NV12,
>>                                          AV_PIX_FMT_NONE };
>>   
>> +    enum AVPixelFormat probed_pix_fmt = (avctx->pix_fmt < 0 ?
> Shouldn't this be <= 0? If unset it will most likely be 0.
> Also, the braces seem unneccesary or misplaced.
>
>> +                                         AV_PIX_FMT_YUV420P :
>> +                                         avctx->pix_fmt);
>> +
>> +    ret = convert_to_cuda_video_chroma_format(probed_pix_fmt, &probed_chroma_format);
>> +    if (ret < 0) {
>> +        // pixel format is not supported:
> Printing an error here would be better, instead of failing init without
> any indication what went wrong.
>
>> +        return ret;
>> +    }
>> +    probed_width = avctx->coded_width ? avctx->coded_width : 1280;
>> +    probed_height = avctx->coded_height ? avctx->coded_height : 720;
>> +
>>       // Accelerated transcoding scenarios with 'ffmpeg' require that the
>>       // pix_fmt be set to AV_PIX_FMT_CUDA early. The sw_pix_fmt, and the
>>       // pix_fmt for non-accelerated transcoding, do not need to be correct
>> @@ -824,7 +873,10 @@ static av_cold int cuvid_decode_init(AVCodecContext *avctx)
>>       if (ret < 0)
>>           goto error;
>>   
>> -    ret = cuvid_test_dummy_decoder(avctx, &ctx->cuparseinfo);
>> +    ret = cuvid_test_dummy_decoder(avctx, &ctx->cuparseinfo,
>> +                                   probed_chroma_format,
>> +                                   probed_width,
>> +                                   probed_height);
>>       if (ret < 0)
>>           goto error;
>>   
>>
>
> LGTM otherwise


This patch was rejected by wm4, so consider it dropped.

     Pavel.


More information about the ffmpeg-devel mailing list