nvenc doesn't support P016, but we have two problems today:
1) We declare support for YUV444P16 which nvenc also doesn't support.
We do this because it's the only pix_fmt we have that can
approximate nvenc's internal format that is YUV444P10 with data in
MSBs instead of LSBs. Because the declared format is a 16bit one,
it will be preferrentially chosen when encoding >10bit content,
but that content will normally be YUV420P12 or P016 which should
get mapped to P010 and not YUV444P10.
2) Transcoding P016 content with nvenc should be possible in a pure
hardware pipeline, and that can't be done if nvenc doesn't say it
accepts P016. By mapping it to P010, we can use it, albeit with
truncation. I have established that swscale doesn't know how to
dither to 10bits so we'd get truncation anyway, even if we tried
to do this 'properly'.
Signed-off-by: Philip Langdale <phil...@overt.org>
---
libavcodec/nvenc.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/libavcodec/nvenc.c b/libavcodec/nvenc.c
index 161c56adc2..e00c1fb245 100644
--- a/libavcodec/nvenc.c
+++ b/libavcodec/nvenc.c
@@ -41,7 +41,8 @@ const enum AVPixelFormat ff_nvenc_pix_fmts[] = {
AV_PIX_FMT_NV12,
AV_PIX_FMT_P010,
AV_PIX_FMT_YUV444P,
- AV_PIX_FMT_YUV444P16,
+ AV_PIX_FMT_P016, // Truncated to 10bits
+ AV_PIX_FMT_YUV444P16, // Truncated to 10bits
AV_PIX_FMT_0RGB32,
AV_PIX_FMT_0BGR32,
AV_PIX_FMT_CUDA,
@@ -52,6 +53,7 @@ const enum AVPixelFormat ff_nvenc_pix_fmts[] = {
};
#define IS_10BIT(pix_fmt) (pix_fmt == AV_PIX_FMT_P010 || \
+ pix_fmt == AV_PIX_FMT_P016 || \
pix_fmt == AV_PIX_FMT_YUV444P16)
#define IS_YUV444(pix_fmt) (pix_fmt == AV_PIX_FMT_YUV444P || \
@@ -1222,6 +1224,7 @@ static NV_ENC_BUFFER_FORMAT nvenc_map_buffer_format(enum
AVPixelFormat pix_fmt)
case AV_PIX_FMT_NV12:
return NV_ENC_BUFFER_FORMAT_NV12_PL;
case AV_PIX_FMT_P010:
+ case AV_PIX_FMT_P016:
return NV_ENC_BUFFER_FORMAT_YUV420_10BIT;
case AV_PIX_FMT_YUV444P:
return NV_ENC_BUFFER_FORMAT_YUV444_PL;
--
2.14.1
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