better mp4 (h.264) derivatives at archive.org!

Late last week, we pushed live a new video deriving technique, as well as in the process updated our audio/video file reader, ffmpeg.

New items will benefit from this newer method, and prior items can be re-derived by users if they desire (probably by the end of the year, we will rederive all our movies automatically).

The video will have significantly less “noise”, a higher PSNR (Peak Signal-to-Noise Ratio), and less”blocking” — all at similar or faster deriving speed to build and the same bitrate and filesize!

example new derivative frame

example new derivative frame

example old derivative frame

example old derivative frame

We now open the source video file up with ffmpeg, resize and convert it to raw video, and pipe it to the most recent build of “x264” tool (opting for baseline profile for iPhone, etc. compatibility).
For the very curious (and the very geeky😉 here is a how we make our h.264 MPEG4 video files now:

• ffmpeg -i camels.avi -vn -acodec libfaac -ab 64k -ac 2 temp.aac
• ffmpeg -an -deinterlace -i camels.avi -s 320x240 -r 20 -vcodec rawvideo -pix_fmt yuv420p -f rawvideo - 2>/dev/null | ffmpeg -an -f rawvideo -s 320x240 -r 20 -i - -f yuv4mpegpipe - 2>/dev/null | x264 --bitrate 512 --vbv-maxrate 768 --vbv-bufsize 1024 --profile baseline --pass 1 /dev/stdin --demuxer y4m -o temp.h264
• ffmpeg -an -deinterlace -i camels.avi -s 320x240 -r 20 -vcodec rawvideo -pix_fmt yuv420p -f rawvideo - 2>/dev/null | ffmpeg -an -f rawvideo -s 320x240 -r 20 -i - -f yuv4mpegpipe - 2>/dev/null | x264 --bitrate 512 --vbv-maxrate 768 --vbv-bufsize 1024 --profile baseline --pass 2 /dev/stdin --demuxer y4m -o temp.h264
• mp4creator -c temp.h264 -r 20 t2.mp4
• mp4creator -c temp.aac -interleave t2.mp4
• ffmpeg -i t2.mp4 -acodec copy -vcodec copy -metadata title="Camels at a Zoo - http://www.archive.org/details/camels" -metadata year="2004" -metadata comment="license:http://creativecommons.org/licenses/by-nc/3.0/" camels_512kb.mp4
• mp4creator -optimize camels_512kb.mp4

–Tracey Jaquith

This entry was posted in Video Archive and tagged , , , , , . Bookmark the permalink.

2 Responses to better mp4 (h.264) derivatives at archive.org!

  1. Beatrice M says:

    Thanks Tracey! I just uploaded a video and I look forward to seeing the results! Thanks for your great work.

  2. Ashwini says:

    It works great, Tracey!

    Can you also add the command line for the gif animation thumbnails?

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