What is the default FFMPEG codec for outputting images and what are alternatives?

Question

I took a look at Default ffmpeg codec when nothing is specified. I see that the default codec is likely libx264 for video. Is this the same answer for using an FFMPEG command to make a JPG?

If it's libx264, what would be a good alternative codec to generate an image? I took a look at https://johnvansickle.com/ffmpeg/git-readme.txt, and I can't seem to find anything on what those codecs do. For example, searching libzimg just comes up with pages of people enabling it in a long list of options. https://ffmpeg.org/ffmpeg-codecs.html has no mention of zimg.

My current command is ffmpeg -loglevel quiet -report -timelimit 9 -timeout 9 -i www.example.com/manifest -vframes 1 output.jpg -y. I want to make sure I know what codec is being used when doing this.

I'm using https://johnvansickle.com/ffmpeg/git-readme.txt, which has mjpeg listed. I just want to be sure that this would be the default, when nothing is specified. (I can specify things going forward, but want to know what would have been used before).

llogan · Accepted Answer · 2020-05-08T18:34:47.683

2

Default JPG encoder is mjpeg. Default encoders are not really documented as it depends on your ffmpeg configuration, but you can refer to the log from your ffmpeg command.

Example:

ffmpeg -i input.mp4 -frames:v 1 output.jpg

Log excerpt:

Output #0, image2, to 'output.jpg':
  Metadata:
    encoder         : Lavf58.42.102
    Stream #0:0: Video: mjpeg, yuvj444p(pc), 320x240 [SAR 1:1 DAR 4:3], q=2-31, 200 kb/s, 25 fps, 25 tbn, 25 tbc

So in this example the default muxer is image2 and the default encoder is mjpeg.

Get more info on these with ffmpeg -h muxer=image2 and ffmpeg -h encoder=mjpeg as shown in What are all codecs and formats supported by FFmpeg?

edited May 08 '20 at 18:34

answered May 08 '20 at 17:59

llogan

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Do you see the documented anywhere? I see it listed as a motion JPG encoder, but not that its default https://ffmpeg.org/ffmpeg-codecs.html#mjpeg – Dave Stein May 08 '20 at 18:00
Basically I need to be extra sure for licensing reasons :) – Dave Stein May 08 '20 at 18:05
@DaveStein It's not documented. Looks like I misunderstood your question. Still not really sure what you're trying to figure out. – llogan May 08 '20 at 18:14
Updated the question. Thanks! – Dave Stein May 08 '20 at 18:24
@DaveStein Updated the answer. – llogan May 08 '20 at 18:35

What is the default FFMPEG codec for outputting images and what are alternatives?

1 Answers1