Quick Guide

MPEG-4 digital cameras:

MP4Cam2AVI doesn't need any codecs to perform mp4 -> avi conversion, but you should install any ISO MPEG-4 compatible codec to view or edit target files. DivX5 is recommended.

1. ISO MPEG-4 compatible VfW codecs

To view or edit target avi files, you should install Video for Windows (VfW) codec with ISO MPEG-4 support (i.e. DivX5, 3ivX, XviD).

Directshow codecs, such as those used by Windows Media player, are not suitable.

Table 1. ISO MPEG-4 compatible VfW codecs (only most common codecs and fourcc's are listed).

Codec name	Acceptable fourcc's*	Status	Download page
DivX 5	DX50, XVID	Freeware	[DOWNLOAD]
XviD	XVID, DX50	Freeware, Open Source	[DOWNLOAD]
3ivX**	3IV2, DX50, XVID	Commercial, 30 days trial	[DOWNLOAD]
FFDShow***	FFDS, DX50, XVID (configurable)	Freeware, Open Source	[DOWNLOAD]

* Since you installed MPEG-4 compatible codec, you should set MP4Cam2AVI FourCC option to one of the acceptable fourcc's for this codec, otherwise target avi file may be unviewable. For example, if you installed DivX and made avi with fourcc '3IV2', file will be 'broken'. After changing fourcc to 'DX50' file will be OK.
To change FourCC of already converted avi files use 'action': 'Many .AVI -> Change FourCC'.

** With 3ivX codec, you can play source .MP4 files with Media Player, but this won't help with video editing apps, most of then don't work with .mp4 container.

*** During FFDShow installation, check 'VfW Interface' option. Otherwise you can't edit target avi's in VirtualDub and other video editing apps.

2. Recommendations for video editing apps
    (VirtualDub, Abobe Premiere, Pinnacle Studio, etc.)

1. First of all, install ISO MPEG-4 compatible VfW codec (i.e. DivX 5), if it's not installed yet. If you don't have such codec installed, avi editor won't import avi files.

Try not to install many codecs or codec packs, cause different codecs may conflict with each other. The best way is to have only one MPEG-4 codec installed.

If you have problems with avi file import, try to remove all MPEG-4 codecs first, then install one codec and try again.

In most cases, DivX codec is recommended - I had no problems with avi editing software when I used DivX codec.

With XviD and FFDShow codecs, I couldn't import avi files to Adobe Premiere Pro, in Pinnacle Studio they imported OK, but file thumbnails were black (with DivX it was fine).

With 3ivX codec files imported fine (Abobe Premiere Pro & Pinnacle Studio), but thumbnails were black.

2. In MP4Cam2AVI, set audio option to 'PCM', this will give better audio/video sync.

3. 'Source audio' option and .MP4 files with AAC sound
    (Sanyo Xacti, Olympus C770, Sony M1 cameras)

Actually, avi container doesn't support AAC sound, so AAC in avi is a dirty hack :). Use this option for preview purposes only (converting with 'Source audio' is 5-10 times faster, than with 'MP3', cause audio recompression requires CPU time).

To play avi files with AAC sound, you should install CoreAAC directshow filter (freeware) or 3ivX codec (commercial).

Most of video editing apps (VirtualDub, Adobe Premiere, etc.) don't understand AAC sound in avi files, use 'PCM' or 'MP3' options.

MJPEG (photo cameras):

MP4Cam2AVI convetrs MJPEG .MOV files to AVI without recomression, target avi's are MJPEG too, they have fourcc 'MJPG' (MP4Cam2AVI doesn't convert them to DivX, it performs direct stream copy conversion). In most cases you don't need to install any codecs to play mjpeg avi files. If you can't play these files, install Morgan Multimedia MJPEG codec.

The easiest way to compress target mjpeg avi files to standard DivX (XviD, etc.) is using VirtualDub. Use Ctrl+E shortcut to open target file in VirtualDub.

Some MJPEG cameras write audio with non-standard sample rates less than 8000 Hz (i.e. 7875 Hz). When you select 'MP3' compression option for such files, audio will be resampled to 8000 Hz (Lame mp3 encoder doesn't work with non-standard sample rates). So, if you want to get maximum audio quality, use 'PCM' or 'Source audio' options (also recommended for further editing).

Nero Recode:

Since version 1.55 MP4Cam2AVI works with MP4 ASP files encoded by Nero Recode (AVC MPEG4 content is not supported).

If source file contains B-frames, there may be problems with 'XVID' fourcc. I don't know why, in some cases XviD codec doesn't play conveted to avi file with B-frames, while 3ivX and DivX do it perfectly.

If source audio track contains more than 2 channels, it will be downmixed to stereo.

FAQ:

Why should I convert .MP4|.MOV files from my camera to .AVI format?

To use them with video editing software - MP4 file format is not supported by most of video editing programs (i.e. Adobe Premiere, Pinnacle Studio etc.).

To play them with hardware DVD-MPEG4 players (they don't understand .mp4 files)

I can't view converted avi file with Windows Media Player. What's wrong?

To view MPEG-4 movie, you should install MPEG-4 compatile codec (DivX, XviD, 3ivX). See quick guide for more details.

To view MJPEG avi file, you should install MJPEG video codec, (i.e. Morgan Multimedia MJPEG codec).
VirtualDub has it's own MJPEG decoder, so it doesn't need any codec to understand MJPEG avi files.

I can't import converted MPEG4 AVI file to Adobe Premiere (Pinnacle Studio, etc.), while Media Player plays it fine. What's wrong?

To import avi files to avi editing app, you should have Video for Windows (VfW) ISO MPEG-4 compatible codec installed. Directshow codecs, such as those used by Windows Media player, are not suitable. DivX codec is recommended (see quick guide for more details)

How to determine whether my .mov files are MPEG-4 or MJPEG?

In MP4Cam2AVI, click file name and see 'file information'.

Why target avi file is so large?

Check audio format option. When it is set to 'PCM', audio is stored without compression. Use 'MP3' or 'Source audio' option to get smaller file.

Does MP4Cam2AVI re-encode audio?

If you choose 'Source audio' option - audio is not re-encoded, but be careful - some programs and hardware mpeg4-dvd players won't work with these files. Also you can convert audio to PCM (best fo further editing) or MP3.

What advantages has MP4Cam2AVI comparing to other programs?

It doesn't re-encode video - just copies data 'as is' from MP4(MOV) container to AVI. So, video quality is not affected, program works much faster than other converters with video recompression (cause video compression requires much CPU time).

It fixes audio/video sync issue. Audio and video lengths in MP4 video fragments are not exactly the same (i.e. for Sanyo/Fisher C1, audio is ~50ms shorter). When you join many video fragments, you will have audio/video desync increasing to the end of the target file. MP4Cam2AVI solves this problem - it inserts silence when audio stream ends or crops 'silent' frames at the end of each fragment.

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