3

I am using FFmbc (a FFmpeg derivative) to transcode some video files to H264 (in a mov wrapper).

I want to specify baseline profile (to reduce CPU usage) but can't figure out how. There doesn't seem to be a simple option to specify this - I understand the profile is derived from whatever options I have specified.

However most examples are for FFmpeg and FFmbc rejects them.

The suggestion to use "-flags2 +bpyramid+wpred+mixed_refs-dct8x8" gives the errors:

[NULL @ 0x101093600] [Eval @ 0x7fff5fbfce20] Undefined constant or missing '(' in 'bpyramid'
[NULL @ 0x101093600] Unable to parse option value "bpyramid+wpred+mixed_refs-dct8x8"
[NULL @ 0x101093600] Error setting option flags2 to value +bpyramid+wpred+mixed_refs-dct8x8.

What am I missing here?

6

Note: This is for recent FFmpeg, not FFmbc, which doesn't use the same option syntax (yet)

You need to use the -profile:v option, which has been introduced in FFmpeg 0.9 (afaik) and is now standard in 1.0.

ffmpeg -i input.mp4 -c:v libx264 -preset fast -profile:v baseline out.mov

Why? -profile was used (and prioritized) for AAC encoding. It's simply ambiguous, therefore you need the stream specfier :v.

  • that's for ffmpeg, ffmbc hasn't moved to the newer "-vprofile" style syntax yet. – stib Dec 20 '12 at 6:12
  • You're right. Back when I wrote this FFmpeg was about to change the whole thing and everything was a little confusing. +1 to you. – slhck Dec 20 '12 at 6:19
4

-profile baseline seems to work for me, using libx264. I use the libx264 presets - for example "slow" gives me the options listed below. there's fast, slow, veryslow and placebo (might be more, can't remember).

stib$ ffmbc -i test.mov -vcodec libx264 -preset slow -profile baseline -acodec libfaac -ab 96k -crf 19 test.mp4
...
[libx264 @ 0x101858c00] profile Constrained Baseline, level 3.1
[libx264 @ 0x101858c00] 264 - core 120 - H.264/MPEG-4 AVC codec - Copyleft 2003-2011 - http://www.videolan.org/x264.html - options: cabac=0 ref=5 deblock=1:0:0 analyse=0x1:0x111 me=umh subme=8 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=0 8x8dct=0 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=6 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=0 weightp=0 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=50 rc=crf mbtree=1 crf=19.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
Output #0, mp4, to 'test.mp4'
1

I also had this issue. I removed the extra space chars present in preset file and it worked for me.

0

To set the baseline profile us the following ffmpeg options. Mobile apps like Neighboors by Ring use baseline profile.

ffmpeg -i in_video.mp4 -vcodec libx264 -acodec aac -b:a 256k -vf scale=1280:720 -profile:v baseline out_video.mp4

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