[FFmpeg-user] FLAC experience so far

[Ferdi Scholten]

On 09-06-2025 01:30, Mark Filipak wrote:
> The source: c:\01.WAV
> 620,398,844 bytes
>
> ffmpeg^
>  -i c:\01.WAV^
>  -map 0^
>  -c flac^
>  "c:\Manual Goettsching [1992] E2-E4.flac.m4a"
>
> Provoked: "Could not find tag for codec flac in stream #0, codec not 
> currently supported in container".
>
> ffmpeg^
>  -i c:\01.WAV^
>  -map 0^
>  -c flac -compression_level 12^
>  "c:\Manual Goettsching [1992] E2-E4.flac.mp4"
> 405,530,095 bytes
>
> The above succeeded. It ran for a 3 or 4 minutes.
>
> ffmpeg^
>  -i c:\01.WAV^
>  -map 0^
>  -c flac^
>  -compression_level 12^
>  -lpc_type cholesky^
>  -exact_rice_parameters 1^
>  -multi_dim_quant 1^
>  "c:\Manual Goettsching [1992] E2-E4.flac .mp4"
>
> The above has been running for 43 minutes and has encoded 17 seconds 
> of a 58 minute audio.
If you want lossless encoding in a m4a container, you should use ALAC 
instead of FLAC. (m4a does not support flac as is correctly stated by 
FFmpeg, mp4 officially also does not support FLAC, but apparently it can 
somehow be fitted in...)

However I found (by encoding multiple audio files with both encoders) 
that FLAC is more efficient than ALAC (both faster and better 
compression) and FLAC has much more versatile metadata support.
Use FLAC's own container, or matroska for full support of the format.