From: Pavel Koshevoy <pkoshe...@gmail.com>
Evidently CUVID doesn't support decoding 422 or 444 chroma formats,
and only a limited set of resolutions per codec are supported.
Unfortunately CUVID silently drops packets for video of unsupported
resolution. However, it will error-out at cuvidCreateDecoder call
if the indicated video resolution is not supported.
Given that stream resolution and pixel format are typically known as
a result of probing it is better to use this information during
avcodec_open2 call to fail immediately, rather than proceeding to
decode and never receiving any frames from the decoder nor receiving
any indication of decode failure.
---
libavcodec/cuvid.c | 62 +++++++++++++++++++++++++++++++++++++++++++++++++-----
1 file changed, 57 insertions(+), 5 deletions(-)
diff --git a/libavcodec/cuvid.c b/libavcodec/cuvid.c
index 8fc713d..f9c29a1 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 ?
+ 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:
+ 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;
--
2.9.2
