On 23/04/15 09:54, Marco Porsch wrote: > Hi, > > when encoding an 8bit grayscale video using the commandline > # ffmpeg.exe -f rawvideo -vcodec rawvideo -pix_fmt gray -s 1280x960 -r 30 -i > out8.yuv -c:v libx264 -qp 0 -preset ultrafast -y out8.mkv > and decoding using > # ffmpeg.exe -i out8.mkv -f rawvideo -c:v rawvideo -pix_fmt gray -y > out8_decoded.yuv > I get two bit-identical .yuv files. Correct. > > When doing the same with a 16bit grayscale video using the command lines > # ffmpeg.exe -f rawvideo -vcodec rawvideo -pix_fmt gray16le -s 1280x960 -r 30 > -i out16.yuv -c:v libx264 -qp 0 -preset ultrafast -y out16.mkv > # ffmpeg.exe -i out16.mkv -f rawvideo -c:v rawvideo -pix_fmt gray16le -y > out16_decoded.yuv > the resulting files are not identical. > > Any explanation for this behavior? Am I doing something wrong? > > Best regards, > --Marco > > > D:\Users\Porsch\Develop\LoggingApp\tools\build\vs12\dl4log_mux>d:\Tools\ffmpeg-20150109-git-d1c6b7b-win32-shared\bin\ffm > peg.exe -f rawvideo -vcodec rawvideo -pix_fmt gray -s 1280x960 -r 30 -i > out8.yuv -c:v libx264 -qp 0 -preset ultrafast -y > out8.mkv > [...] > [libx264 @ 0093cfe0] profile High 4:4:4 Predictive, level 3.2, 4:4:4 8-bit > [...] >
> D:\Users\Porsch\Develop\LoggingApp\tools\build\vs12\dl4log_mux>d:\Tools\ffmpeg-20150109-git-d1c6b7b-win32-shared\bin\ffm > peg.exe -f rawvideo -vcodec rawvideo -pix_fmt gray16le -s 1280x960 -r 30 -i > out16.yuv -c:v libx264 -qp 0 -preset ultrafa > st -y out16.mkv >[...] > [libx264 @ 0071d140] profile High 4:4:4 Predictive, level 3.2, 4:4:4 8-bit > [...] In both cases you have created an 8bit h264 file, why would you then expect the conversion back to be bit exact? (x264 supports 8 or 10 bit and needs compiling explicitely for the required bit depth) -- Tim. Key Fingerprint 38CF DB09 3ED0 F607 8B67 6CED 0C0B FC44 8B0B FC83 _______________________________________________ ffmpeg-user mailing list [email protected] http://ffmpeg.org/mailman/listinfo/ffmpeg-user
