Changes between Version 44 and Version 45 of HWAccelIntro

Timestamp:

Dec 6, 2016, 4:40:39 AM (10 years ago)

Author:

Philip Langdale

Comment:

Update discussion of CUVID (Remove h.263. Discuss 10bit decode and transcode situation)

HWAccelIntro

@@ -55 +55 @@
 † Actually yes, but is deprecated for technical reasons and should not be used.
 
-^1^ Also known as "CUDA Video Decoding API" or "CUVID."
+^1^ Also known as "CUDA Video Decoding API" or "CUVID" or "NvDecode".
 
 ^2^ See NVENC
@@ -139 +139 @@
 }}}
 
-== CUDA/CUVID ==
+== CUDA/CUVID/NvDecode ==
 
 CUVID, which is also called nvdec by Nvidia now, can be used for decoding on Windows and Linux.
 In combination with nvenc it offers full hardware transcoding.
 
-CUVID offers decoders for H264, HEVC, H263, MJPEG, mpeg1/2/4, vp8/9, vc1.
+CUVID offers decoders for H264, HEVC, MJPEG, mpeg1/2/4, vp8/9, vc1.
 Codec support varies by hardware. The full set of codecs being available only on Pascal hardware, which adds VP9 and 10 bit support.
 
-While decoding 10 bit video is supported, CUVID is only able to output 8 bit video, so the additional 2 bits are lost in the process.
+While decoding 10 bit video is supported, it is not possible to do full hardware transcoding currently (See the partial hardware example below).
 
 Sample decode using CUVID, the cuvid decoder copies the frames to system memory in this case:
@@ -157 +157 @@
 {{{
 ffmpeg -hwaccel cuvid -c:v h264_cuvid -i input -c:v h264_nvenc -preset slow output.mkv
+}}}
+
+Partial hardware transcode, with frames passed through system memory (This is necessary for transcoding 10bit content):
+{{{
+ffmpeg -c:v h264_cuvid -i input -c:v h264_nvenc -preset slow output.mkv
 }}}