Remux MOV to MP4 without re-encode

[hanen87]

Hi,

Does anyone know the best software to remux avc & aac stream without re-encode?

I've try to remux a trailer from apple.com with MP4BOX but it re-encode the audio to VBR instead of keeping it in CBR untouched condition

Edit: I'm confuse now. Does the difference in bit rate between the source and the final result means MP4BOX re-encode them?

http://img205.imageshack.us/img205/8375/mp41ay4.jpg

[Placio74]

MP4Box can't reencode audio/video. It's not possible.

Demux audio from original .mov file and from .mp4 (as .aac RAW) - compare both.

BTW
Use MediaInfo and check .mov file - change view to text and look at audio bitrate. There is Bit rate and Nominal bit rate - it's little different.

Maybe MP4Box 'think' it's VBR...?

[hanen87]

Thanks for reply.

The AAC track in MOV shows as CBR in MediaInfo. However, the extracted AAC track (with MP4BOX) is VBR. Any idea what happen?

Edit: why MP4BOX convert the AVC stream to 25.000FPS when i extract to raw format?

[microchip8]

Thanks for reply.

The AAC track in MOV shows as CBR in MediaInfo. However, the extracted AAC track (with MP4BOX) is VBR. Any idea what happen?

Edit: why MP4BOX convert the AVC stream to 25.000FPS when i extract to raw format?

AFAIK, AAC doesn't have a CBR mode, it's only VBR. Also MP4Box can't automatically detect the FPS of a raw stream. For this reason you have to specify the FPS when muxing with the -fps option

[hanen87]

http://forum.doom9.org/showthread.php?s=&threadid=68300#post424070

AAC do have CBR mode ;)

AFAIK, AAC doesn't have a CBR mode, it's only VBR. Also MP4Box can't automatically detect the FPS of a raw stream.

Can you give an example for the command line?

For this reason you have to specify the FPS when muxing with the -fps option

[Placio74]

Some other...
Use MPEG Streamclip (http://www.squared5.com/) - Open MOV file and Save as - change file type to MP4.

Before:
F:\Sig2006_fullres.mov
General
Complete name : F:\Sig2006_fullres.mov
Format : QuickTime
Format/Info : Quictime movie
Format/Family : MPEG-4
File size : 223 MiB
PlayTime : 13mn 45s
Bit rate : 2270 Kbps
StreamSize : 476 KiB
Encoded date : UTC 2006-07-27 10:51:25
Tagged date : UTC 2006-07-27 15:02:48
Video #2
Codec : H.264
Codec/Info : H.264 (3GPP)
PlayTime : 13mn 45s
Bit rate : 2110 Kbps
Nominal bit rate : 2064 Kbps
Width : 768 pixels
Height : 576 pixels
Display Aspect ratio : 4/3
Frame rate : 25.000 fps
StreamSize : 208 MiB
Encoded date : UTC 2006-07-27 10:51:26
Tagged date : UTC 2006-07-27 15:02:48
Audio #1
Codec : AAC LC
Codec/Info : AAC Low Complexity
PlayTime : 13mn 45s
Bit rate : 155 Kbps
Nominal bit rate : 160 Kbps
Bit rate mode : CBR
Channel(s) : 2 channels
Channel positions : L R
Sampling rate : 44.1 KHz
Resolution : 16 bits
StreamSize : 15.3 MiB
Encoded date : UTC 2006-07-27 10:51:26
Tagged date : UTC 2006-07-27 15:02:48


After:
F:\Sig2006_fullres.mp4
General
Complete name : F:\Sig2006_fullres.mp4
Format : MPEG-4
Format/Info : ISO 14496-1 version 2
Format/Family : MPEG-4
File size : 223 MiB
PlayTime : 13mn 45s
Bit rate : 2270 Kbps
StreamSize : 515 KiB
Encoded date : UTC 2008-01-15 13:38:47
Tagged date : UTC 2008-01-15 13:39:35
Video #2
Codec : H.264
Codec/Info : H.264 (3GPP)
PlayTime : 13mn 45s
Bit rate : 2110 Kbps
Nominal bit rate : 2065 Kbps
Width : 768 pixels
Height : 576 pixels
Display Aspect ratio : 4/3
Frame rate : 25.000 fps
StreamSize : 208 MiB
Language : English
Encoded date : UTC 2008-01-15 13:38:41
Tagged date : UTC 2008-01-15 13:39:35
Audio #1
Codec : AAC LC
Codec/Info : AAC Low Complexity
PlayTime : 13mn 45s
Bit rate : 155 Kbps
Nominal bit rate : 160 Kbps
Bit rate mode : CBR
Channel(s) : 2 channels
Channel positions : L R
Sampling rate : 44.1 KHz
Resolution : 16 bits
StreamSize : 15.3 MiB
Language : English
Encoded date : UTC 2008-01-15 13:38:41
Tagged date : UTC 2008-01-15 13:39:35

[hanen87]

Thank you very much Placio74. It's a very handy tool for remuxing AVC & AAC streams without re-encode. However, it doesn't mux AAC track with 5.1 Channels :(

[Placio74]

Some other...
FFmpeg (http://ffdshow.faireal.net/mirror/ffmpeg/)
From command line:
ffmpeg -i name_file.mov -vcodec copy -acodec copy name_file.mp4

And other...
Avidemux (http://mulder.dummwiedeutsch.de/home/?page=projects#avidemux)
Just open .mov file, leave Copy for audio and video, change container (Format) to MP4 and save (type name file and extension).

[EDIT]

Hmm... multichannel AAC?

Avidemux = change to stereo.
MPEG Streamclip = can't copy multichannel audio.
FFmpeg and Yamb (MP4Box) = not change channels.

[hanen87]

Thank you again Placio74. Hmm... Seems like there's still don't have a suitable tool for MP4 with multi channels AAC

[foxyshadis]

http://forum.doom9.org/showthread.php?s=&threadid=68300#post424070

AAC do have CBR mode ;)

There's no such thing as CBR and VBR in modern audio codecs, only encoder implementations. There's no overall signaling in the bitstream or the container, only for the size of each packet. iTunes just never bothered to design a smart bitrate switching.

So I don't even see the point of mediainfo printing the information, but I'm sure the only reason it's different is that takes an inaccurate hint from one or the other.

[Kurtnoise]

you can have the max bitrate & average bitrate values stored in the esds atom. That's why the result can differ if we use these values...