4GB wav file limit when converting audio? about ifme HOT 10 CLOSED

This likely issue on FFmpeg and Filesystem currently, setting Temp folder on FAT32 not recommended

from ifme.

I'm running on NTFS. I think the error is with the wav format itself. Looking at the ffmpeg code it just spits out an error if the wav file size reaches a defined limit in the header.

Anyways this is an interesting problem, any DTS audio in a 2+ hour movie will not be processed correctly.

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WAV files are usually stored uncompressed, which means that they can get quite large, but they cannot exceed 4 gigabytes due to the fact that the file size header field is a 32-bit unsigned integer (32 bit file length means a maximum of 4 gigs).

I think, change to need pipe method directly to audio encoder, instead of generate wav first.

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Yep, that would be a good solution.

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Yea... before I plan to do this, found out some encoder didn't support pipe/stdin.
Now best time to change, cons is, cannot show current %

for audio, I think no need to worry about progress and time remaining

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Maybe do some simple maths first before starting encode, to select whether to pipe or not? Or you could split the audio file when it hits 4 GB?

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By simple maths I mean something like:
Estimated Filesize in KB = ( ( Num-channels * Average-KbpsBitrate-for-single-channel ) * length-in-seconds ) / 8

The Bitrate might be something around 1100Kbps for a single channel? You might have to do some testing, but using that number and a movie that's 2hr14min43sec long with 6.1:

( ( 7 * 1100 ) * 8023 ) / 8 = 7,722,137.5 KB = 7.3644 GB

Then you'd know to either split the file, or pipe it instead.

from ifme.

That also good solution, but with pipe also reduce Disk I/O.
Doom9 forums says:

No stdin = useless for me if I can't use with Virtualdub's external encoder.

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From now on, IFME using pipe (signed & little endian)

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instruct FFmpeg to use -acodec pcm_s16le -f wav for example, pipe with wav header

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