[FFmpeg-user] Post problem: export long wav files (incorrect/limited length)

[Paul B Mahol]

On 11/19/12, Stas Fomin <stas-fomin at yandex.ru> wrote:
>
>
> 19.11.2012, 06:00, "Dave Rice" <dave at dericed.com>:
>> On Nov 18, 2012, at 6:36 PM, Stas Fomin wrote:
>>
>
>> You can't store more than 4 gigabytes in WAV. For workarounds you could:
>> - use WAVE 64, but FFmpeg supports w64 for demuxing but not muxing (could
>> submit a ticket).
>> - use multiple output files to export segments in files that are smaller
>> enough for the WAV format size constraints
>> - use another file format that doesn't have this size constraints: AIFF,
aiff does have size constraint
>> MOV, MKA, NUT, etc
>
> Actually, I have to export to some lossless audio format, to process
> audiofile with some audioeditor (denoise, compressor, etc). Any lossy format
> is not an option for audio postproduction because efficient denoising is
> impossible.
>
> And some facts:
> * Audacity support long WAVs (import/export), 9hours -- OK.

And ffmpeg reports such files as w64 and not wav?

> * VirtualDub exports long WAV from video (and Audacity successfully opens
> it!).
> ** So technically it is possible (long continous wav with length > 4GB)!
> * ffmpeg export to AIFF have the same problem, as export to WAV -- big file,
> but duration only "2:13:00".
> ** Other formats is not an option because of lossy or because nothing can
> work with (W64).
> *  Yes, now I use workaround to manually split exported WAV files to several
> chunks but it breaks my automated toolchain for batch videoprocessing (where
> ffmpeg is one of the core part)
>
> Well, it is pity.  I hoped that may be there are some magic option to fix
> the problem, but the world is not perfect (But I still have a little hope..)

Do you need w64 muxer?