I am unable to re-encode an H.264 video that I downloaded from Youtube back to its original size. The MediaInfo is pasted below. The size of the video stream is 20 MB.
I decoded the video into raw YUV (using ffmpeg and JM separately, ensuring that I get an identical file). Then I re-encoded it using the x264 library with a variety of configs. The encoded H.264 videos that I generated are around 40 MB in size.
This is the commandline that I used:
x264 -o out.h264 --input-res 1280x720 --preset slow autl.yuv
Any ideas on what options I might be missing that YouTube would have used to encode the video?
Mediainfo:
General
Complete name : autl.h264
Format : AVC
Format/Info : Advanced Video Codec
File size : 19.9 MiB
Writing library : x264 core 155 r2901 7d0ff22
Video
Format : AVC
Format/Info : Advanced Video Codec
Format profile : [email protected]
Format settings : CABAC / 3 Ref Frames
Format settings, CABAC : Yes
Format settings, Reference frames : 3 frames
Width : 1 280 pixels
Height : 720 pixels
Display aspect ratio : 16:9
Frame rate mode : Variable
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Writing library : x264 core 155 r2901 7d0ff22
Color range : Limited
Color primaries : BT.709
Transfer characteristics : BT.709
Matrix coefficients : BT.709
