[FFmpeg-trac] #210(undetermined:new): bit depth loss with 'lossless' encoding!

[FFmpeg]

#210: bit depth loss with 'lossless' encoding!
--------------------------+-----------------------
 Reporter:  Atrocia       |        Type:  defect
   Status:  new           |    Priority:  critical
Component:  undetermined  |     Version:  git
 Keywords:                |  Blocked By:
 Blocking:                |  Reproduced:  0
 Analyzed:  0             |
--------------------------+-----------------------
 I have 48 KHz / 24 bit audio files created by the Zoom H1 audio recorder;
 e.g.:

 $ mediainfo sample.WAV
 General
 Complete name                    : sample.WAV
 Format                           : Wave
 File size                        : 2.75 MiB
 Duration                         : 10s 0ms
 Overall bit rate                 : 2 304 Kbps

 Audio
 ID                               : 0
 Format                           : PCM
 Format settings, Endianness      : Little
 Codec ID                         : 1
 Codec ID/Hint                    : Microsoft
 Duration                         : 10s 0ms
 Bit rate                         : 2 304 Kbps
 Channel(s)                       : 2 channels
 Sampling rate                    : 48.0 KHz
 Bit depth                        : 24 bits
 Stream size                      : 2.75 MiB (100%)

 When I convert them to flac format, they become 16 bit:

 $ ffmpeg -i sample.WAV sample.flac

 ...


 $ mediainfo sample.flac
 General
 Complete name                    : sample.flac
 Format                           : FLAC
 Format/Info                      : Free Lossless Audio Codec
 File size                        : 695 KiB
 Duration                         : 10s 0ms
 Overall bit rate                 : 569 Kbps
 Writing application              : Lavf53.0.3

 Audio
 Format                           : FLAC
 Format/Info                      : Free Lossless Audio Codec
 Duration                         : 10s 0ms
 Bit rate mode                    : Variable
 Bit rate                         : 563 Kbps
 Channel(s)                       : 2 channels
 Sampling rate                    : 48.0 KHz
 Bit depth                        : 16 bits
 Stream size                      : 687 KiB (99%)
 Writing library                  : Lavf53.0.3

 ffmpeg (git-N-29954-gfc19379) throws this warning - I don't know if it's
 relevant:

 Incompatible sample format 's32' for codec 'flac', auto-selecting format
 's16'

 The 'flac' tool, from the flac project, handles these files correctly:

 $ flac sample.WAV

 ...

 $ mediainfo sample.flac
 General
 Complete name                    : sample.flac
 Format                           : FLAC
 Format/Info                      : Free Lossless Audio Codec
 File size                        : 1.59 MiB
 Duration                         : 10s 0ms
 Overall bit rate                 : 1 336 Kbps

 Audio
 Format                           : FLAC
 Format/Info                      : Free Lossless Audio Codec
 Duration                         : 10s 0ms
 Bit rate mode                    : Variable
 Bit rate                         : 1 329 Kbps
 Channel(s)                       : 2 channels
 Sampling rate                    : 48.0 KHz
 Bit depth                        : 24 bits
 Stream size                      : 1.58 MiB (100%)
 Writing library                  : libFLAC 1.2.1 (UTC 2007-09-17)

 flac gives this warning - no idea if this is related to the one ffmpeg
 gives:

 sample.WAV: WARNING: legacy WAVE file has format type 1 but bits-per-
 sample=24

-- 
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/210>
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