I am using ffmpeg to convert videos to mp4 format. Everything works fine except with MOV format.

The command I use for everything is:

ffmpeg -i input.mov -strict experimental -sameq -s vga -aspect 1.7777 -vcodec libx264 -preset fast -crf 22 -y output.mp4

but the output I keep getting is:

ffmpeg version 0.9, Copyright (c) 2000-2011 the FFmpeg developers
built on Mar 12 2012 11:01:05 with gcc 4.4.5
configuration: --enable-libx264 --enable-gpl --disable-yasm
  libavutil    51. 32. 0 / 51. 32. 0
  libavcodec   53. 42. 0 / 53. 42. 0
  libavformat  53. 24. 0 / 53. 24. 0
  libavdevice  53.  4. 0 / 53.  4. 0
  libavfilter   2. 53. 0 /  2. 53. 0
  libswscale    2.  1. 0 /  2.  1. 0
  libpostproc  51.  2. 0 / 51.  2. 0
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x21767a0] Referenced QT chapter track not found

Seems stream 0 codec frame rate differs from container frame rate: 30.00 (30/1) -> 30.07 (2225/74)
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'input.mov':
  Metadata:
    creation_time   : 2009-04-04 07:12:29
    comment         : EASTMAN KODAK COMPANY  KODAK Z1275 ZOOM DIGITAL CAMERA
    comment-eng     : EASTMAN KODAK COMPANY  KODAK Z1275 ZOOM DIGITAL CAMERA
  Duration: 00:00:17.76, start: 0.000000, bitrate: 8100 kb/s
    Stream #0:0(eng): Video: mpeg4 (Advanced Simple Profile) (mp4v / 0x7634706D), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], 7968 kb/s, 30.07 fps, 30.07 tbr, 8544k tbn, 30 tbc
    Metadata:
      creation_time   : 2009-04-04 07:12:29
      handler_name    : 
    Stream #0:1(eng): Audio: pcm_mulaw (ulaw / 0x77616C75), 16000 Hz, 1 channels, s16, 128 kb/s
    Metadata:
      creation_time   : 2009-04-04 07:12:29
      handler_name    : 
[buffer @ 0x2187f00] w:1280 h:720 pixfmt:yuv420p tb:1/1000000 sar:1/1 sws_param:
[scale @ 0x219c120] w:1280 h:720 fmt:yuv420p -> w:640 h:480 fmt:yuv420p flags:0x4
[libx264 @ 0x2190d20] using SAR=4/3
[libx264 @ 0x2190d20] using cpu capabilities: none!
[libx264 @ 0x2190d20] profile High, level 3.0
[libx264 @ 0x2190d20] 264 - core 120 - H.264/MPEG-4 AVC codec - Copyleft 2003-2012 - http://www.videolan.org/x264.html - options: cabac=1 ref=2 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=6 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=12 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=1 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=30 rc=crf mbtree=1 crf=22.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
[aac @ 0x21917e0] Too many bits per frame requested
Output #0, mp4, to 'output.mp4':
  Metadata:
    creation_time   : 2009-04-04 07:12:29
    comment         : EASTMAN KODAK COMPANY  KODAK Z1275 ZOOM DIGITAL CAMERA
    comment-eng     : EASTMAN KODAK COMPANY  KODAK Z1275 ZOOM DIGITAL CAMERA
    Stream #0:0(eng): Video: h264, yuv420p, 640x480 [SAR 4:3 DAR 16:9], q=-1--1, 90k tbn, 30.07 tbc
    Metadata:
      creation_time   : 2009-04-04 07:12:29
      handler_name    : 
    Stream #0:1(eng): Audio: aac, 16000 Hz, 1 channels, s16, 128 kb/s
    Metadata:
      creation_time   : 2009-04-04 07:12:29
      handler_name    : 
Stream mapping:
  Stream #0:0 -> #0:0 (mpeg4 -> libx264)
  Stream #0:1 -> #0:1 (pcm_mulaw -> aac)
Error while opening encoder for output stream #0:1 - maybe incorrect parameters such as bit_rate, rate, width or height

It seems the problem is with audio's bit per frame. Which might be the right solution?

回答1:

The "Too many bits per frame requested" error is coming from the native FFmpeg AAC encoder (-c:a aac). You can use one or more of the following solutions:

Update your `ffmpeg`

Development is very active and the native FFmpeg AAC encoder has seen many improvements; it will now automatically clamp to the max number of bits per frame instead of failing with this error. See the FFmpeg Download page for links to already compiled binaries which are the easiest method to get a recent ffmpeg.

If you're stuck with an old, outdated, ancient `ffmpeg`:

Increase the audio sampling rate such as by adding -ar 44100.
Decrease your bitrate. Default is probably -b:a 128k. Try lower values until it works.
Use -c:a copy to stream copy (re-mux) the audio, and, because MP4 doesn't support pcm_mulaw, use different output container format such as Matroska (.mkv).
Use a different AAC encoder such as libfdk_aac if your ffmpeg supports it.