Re: Creating mjpeg,adpcm AVIs?

Hi Georg

Thanks for that, I'd somehow managed to overlook the -p flag in the 
transcode manual page, and hadn't worked out the significance of the -N 
audio format flags. In fact, however, transcode doesn't seem to directly 
support the audio format I need (0x11 for imaadpcm). However, it turned 
out that ffmpeg would remux the audio without reencoding it, so the 
following sequence works...

DIR=.
BASENAME=somexvid

# extract the video, resize and encode
transcode -i $DIR/$BASENAME.avi -o ${BASENAME}_mjpeg.avi \
    -x ffmpeg,null -Z 320x240 -y ffmpeg,null -F mjpeg

# extract the audio, resample to mono at 22050
transcode -i $DIR/$BASENAME.avi -o ${BASENAME}_pcm.wav \
    -x null,mp3 -y null,wav -a 1 -E 22050,0,1 -Jresample

# re-encode audio to ima_adpcm
sox ${BASENAME}_pcm.wav -i ${BASENAME}_ima_adpcm.wav

# remux
ffmpeg -vcodec copy -i ${BASENAME}_mjpeg.avi \
    -acodec copy -i ${BASENAME}_ima_adpcm.wav \
    ${BASENAME}_mjpeg_ima_adpcm.avi

...and the resulting files play on the camera (A casio exilim ex-z500)!

cheers
guy



Georg Martius wrote:
> Hi Guy,
>
> AFAIK you can do 
>
> transcode -i somexvidfile.avi -p camfile_imaadpcm.wav -o camfile.avi -Z 
> 320x240 -y ffmpeg,raw -F mjpeg
>
> and maybe a -N 0x01 additionally. 
> BTW:  the cameras from cannon and panasonic I had so far used only 8000 kHz.
>
> Hope it helped!
> 	Georg
>
> On Monday 30 March 2009, Guy Hindell wrote:
>   
>> Hi there --- I guess this is a somewhat academic question, but...
>>
>> Can anyone tell me if and how transcode (perhaps via ffmpeg, avimerge
>> etc.) can *encode* AVI files as mjpeg video with ima_adpcm audio? Why do
>> I want to do this? Well, I'm curious to see whether I can create files
>> in the same format as those produced by a Casio Exilim digital camera
>> such that they can be copied to the SD card and the camera will play them.
>>
>> So far I can create files whose video content does play on the camera...
>>
>> transcode -i somexvidfile.avi -o camfile.avi -Z 320x240 -y ffmpeg -F mjpeg
>>
>> but whose audio is still the mp3 encoded 2 channel 44100Hz of the
>> original. The target audio is (I think) 1 channel 22050Hz encoded as
>> ima-adpcm. I've not been able to figure out how I can get ffmpeg to
>> create such audio, or how I can get transcode to use ffmpeg to do it
>> even if it could. However, the audio can be extracted like this...
>>
>> trasncode -i somexvidfile.avi -o camfile_pcm.wav -E 22050,0,1 -x
>> null,raw -y wav
>>
>> and sox used to convert from pcm to ima_adpcm...
>>
>> sox camfile_pcm.wav -i camfile_imaadpcm.wav
>>
>> and an avi with video but no sound is easy enough to create.
>>
>> But... that's as far as I've got --- can transcode create an AVI that
>> combines my camfile.avi and camfile_imaadpcm.wav?
>>
>> cheers
>> guy
>>     
>
>
>
>