FFmpeg Hardware Acceleration with NVENC produces Half Green output video

Question

Using the FFmpeg build found here: https://github.com/illuspas/ffmpeg-hw-win32

gcc 5.3.0
--enable-nvenc nvidia_video_sdk_6.0.1
--enable-libmfx Intel(R)_Media_SDK_2016.0.1
--enable-libfdk-aac 0.1.4
--enable-libspeex 1.2rc1
--enable-libx264 1:148.20150725
--enable-libopenh264 1.5.0
--enable-libx265 1.8
--enable-libopus 1.1.2
--enable-libmp3lame 3.99.5
--enable-libkvazaar 0.8.2

./configure --prefix=/home/aliang/FFmpeg/x86_64 --enable-small --disable-debug --disable-doc --arch=x86_64 --cc='ccache x86_64-w64-mingw32-gcc' --cross-prefix=x86_64-w64-mingw32- --enable-cross-compile --target-os=mingw32 --enable-libfdk-aac --enable-libmp3lame --enable-libopus --enable-libspeex --enable-libx264 --enable-libx265 --enable-libmfx --enable-nvenc --enable-libopenh264 --enable-libkvazaar --enable-gpl --enable-nonfree

I'm running Windows on a MacBook Pro. I also tried with a more recent build and had the same output.

Input video is from sample-videos.com.

The ffmpeg command I am running is:

ffmpeg -y -i sample.mp4 -vcodec nvenc_h264 -pixel_format yuv420p -f mp4 sample-out-nvenc.mp4

sample-out-nvenc.mp4 looks like this via ffplay or vlc:

When I grab a frame using jpeg2, the colors appear normal, but the height is squished.

ffmpeg -y -ss 15.5 -i sample.mp4 -vframes 1 -s 480x300 -f image2 grab.jpg

The ffprobe results for the output (sample-out-nvenc.mp4):

Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'sample-out-nvenc.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf57.25.100
  Duration: 00:00:31.02, start: 0.021333, bitrate: 1994 kb/s
    Stream #0:0(und): Video: h264 (avc1 / 0x31637661), yuv420p(tv), 640x480 [SAR 1:1 DAR 4:3], 1650 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)
    Metadata:
      handler_name    : VideoHandler
    Stream #0:1(und): Audio: aac (mp4a / 0x6134706D), 48000 Hz, 5.1, fltp, 342 kb/s (default)
    Metadata:
      handler_name    : SoundHandler

Lastly the output from the nvenc encoding command:

ffmpeg -y -i sample.mp4 -vcodec nvenc_h264 -pixel_format yuv420p -f mp4 sample-out-nvenc.mp4
ffmpeg version 3.0 Copyright (c) 2000-2016 the FFmpeg developers
  built with gcc 5.3.0 (GCC)
  configuration: --prefix=/home/aliang/FFmpeg/x86_64 --enable-small --disable-debug --disable-doc --arch=x86_64 --cc='ccache x86_64-w64-mingw32-gcc' --cross-prefix=x86_64-w64-mingw32- --enable-cross-compile --target-os=mingw32 --enable-libfdk-aac --enable-libmp3lame --enable-libopus --enable-libspeex --enable-libx264 --enable-libx265 --enable-libmfx --enable-nvenc --enable-libopenh264 --enable-libkvazaar --enable-gpl --enable-nonfree
  libavutil      55. 17.103 / 55. 17.103
  libavcodec     57. 24.102 / 57. 24.102
  libavformat    57. 25.100 / 57. 25.100
  libavdevice    57.  0.101 / 57.  0.101
  libavfilter     6. 31.100 /  6. 31.100
  libswscale      4.  0.100 /  4.  0.100
  libswresample   2.  0.101 /  2.  0.101
  libpostproc    54.  0.100 / 54.  0.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'sample.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    creation_time   : 1970-01-01 00:00:00
    encoder         : Lavf53.24.2
  Duration: 00:00:31.00, start: 0.000000, bitrate: 1353 kb/s
    Stream #0:0(und): Video: h264 (avc1 / 0x31637661), yuv420p, 640x480 [SAR 1:1 DAR 4:3], 966 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)
    Metadata:
      creation_time   : 1970-01-01 00:00:00
      handler_name    : VideoHandler
    Stream #0:1(und): Audio: aac (mp4a / 0x6134706D), 48000 Hz, 5.1, fltp, 383 kb/s (default)
    Metadata:
      creation_time   : 1970-01-01 00:00:00
      handler_name    : SoundHandler
Output #0, mp4, to 'sample-out-nvenc.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf57.25.100
    Stream #0:0(und): Video: h264 (nvenc_h264) ([33][0][0][0] / 0x0021), yuv420p, 640x480 [SAR 1:1 DAR 4:3], q=-1--1, 2000 kb/s, 25 fps, 12800 tbn, 25 tbc (default)
    Metadata:
      creation_time   : 1970-01-01 00:00:00
      handler_name    : VideoHandler
      encoder         : Lavc57.24.102 nvenc_h264
    Side data:
      unknown side data type 10 (24 bytes)
    Stream #0:1(und): Audio: aac ([64][0][0][0] / 0x0040), 48000 Hz, 5.1, fltp, 341 kb/s (default)
    Metadata:
      creation_time   : 1970-01-01 00:00:00
      handler_name    : SoundHandler
      encoder         : Lavc57.24.102 aac
Stream mapping:
  Stream #0:0 -> #0:0 (h264 (native) -> h264 (nvenc_h264))
  Stream #0:1 -> #0:1 (aac (native) -> aac (native))
Press [q] to stop, [?] for help
frame=  774 fps=253 q=-0.0 Lsize=    7551kB time=00:00:30.99 bitrate=1995.6kbits/s speed=10.1x
video:6236kB audio:1297kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.243011%
[aac @ 000001cdd9900520] Qavg: 743.457

It looks like a FFmpeg related bug somewhere between command line and NVENC, however it's hardly a programming question (unless you dig FFmpeg source code of course). — Roman R., Jun 04 '16 at 20:31
Yeah, you're right. Although, I did discover a solution by using `-pix_fmt nv12`, which produces an excellent result. I'll find somewhere else to post it. — Dan Sandland, Jun 05 '16 at 00:24
Does the issue occur with a build of `ffmpeg` from current git master branch? — llogan, Jun 05 '16 at 01:56
@LordNeckbeard Not sure if the issue occurs with the current master; I used the latest release from February, 2016 (3.0). — Dan Sandland, Jun 05 '16 at 04:27
Looks like the UV samples are being co-sited with the top-half of the image, with no stagger.. BTW, your JPEG command is resizing, hence the squished image. Also, `pixel_format` is not a valid option for mp4 output, although it doesn't make a difference here, since it defaults to yuv420p. — Gyan, Jun 05 '16 at 07:15
Oh of course, the resizing, thanks. I thought at first that `pixel_format` had no effect (the output would always register as yuv420p). But I believe it is a valid option here since it works when specifying `nv12` as the pixel format and the [FFmpeg NVENC documentation](https://trac.ffmpeg.org/wiki/HWAccelIntro#NVENC) recommends specifying a supported format. Apparently nv12 is a yuv420p variant and is ["the preferred 4:2:0 pixel format" according to Microsoft](http://www.fourcc.org/yuv.php#NV12). — Dan Sandland, Jun 05 '16 at 09:33

score 2 · Answer 1 · answered Jun 17 '16 at 06:17

I had exactly the same problem, with a GTX 980. This started after installing driver update 368.22. I downloaded and reverted to driver version 365.19 from the nividia driver archive and the problem went away.

So it appears to affect all nvidia cards and drivers.

Mitresthen · Answer 2 · 2016-06-13T11:26:36.953

1

I experienced the same problem with nvenc through another usecase. It seems to have been caused by the latest nvidia quadro driver. The problem was resolved when I reverted it. As you have a macbook, I guess it's fair to assume you don't have a quadro card, but it still might be a driver problem.

edited Jun 13 '16 at 11:26

answered Jun 13 '16 at 10:47

Mitresthen

11
2

FFmpeg Hardware Acceleration with NVENC produces Half Green output video

2 Answers2