[FFmpeg-trac] #5282(ffprobe:new): ffmpeg / ffprobe fail to detect the correct bit depth for some 24 bit DTS streams.

[FFmpeg]

#5282: ffmpeg / ffprobe fail to detect the correct bit depth for some 24 bit DTS
streams.
---------------------------------+----------------------------------
             Reporter:  mario78  |                     Type:  defect
               Status:  new      |                 Priority:  normal
            Component:  ffprobe  |                  Version:
             Keywords:  dts      |               Blocked By:
             Blocking:           |  Reproduced by developer:  0
Analyzed by developer:  0        |
---------------------------------+----------------------------------
 == Summary of the bug: ==
 ffmpeg / ffprobe fail to detect the correct bit depth for some 24 bit DTS
 streams.

 The streams are embedded in a mkv file.

 MediaInfo reports the following:

 {{{
 Audio #1
 ID                                       : 2
 Format                                   : DTS
 Format/Info                              : Digital Theater Systems
 Mode                                     : 16
 Format settings, Endianness              : Big
 Codec ID                                 : A_DTS
 Duration                                 : 58mn 13s
 Bit rate mode                            : Constant
 Bit rate                                 : 1 509 Kbps
 Channel(s)                               : 6 channels
 Channel positions                        : Front: L C R, Side: L R, LFE
 Sampling rate                            : 48.0 KHz
 Frame rate                               : 93.750 fps (512 spf)
 Bit depth                                : 24 bits
 Compression mode                         : Lossy
 Stream size                              : 628 MiB (5%)
 Title                                    : DTS 5.1 @ 1509/768 Kbps
 Language                                 : German
 Default                                  : Yes
 Forced                                   : Yes

 Audio #2
 ID                                       : 3
 Format                                   : DTS
 Format/Info                              : Digital Theater Systems
 Format profile                           : MA / Core
 Mode                                     : 16
 Format settings, Endianness              : Big
 Codec ID                                 : A_DTS
 Duration                                 : 58mn 13s
 Bit rate mode                            : Variable / Constant
 Bit rate                                 : Unknown / 1 509 Kbps
 Channel(s)                               : 6 channels
 Channel positions                        : Front: L C R, Side: L R, LFE
 Sampling rate                            : 48.0 KHz
 Frame rate                               : 93.750 fps (512 spf)
 Bit depth                                : 24 bits
 Compression mode                         : Lossless / Lossy
 Title                                    : ~ DTS-HD MA 5.1 @ 24bit
 Language                                 : English
 Default                                  : No
 Forced                                   : No
 }}}

 However, ffprobe -show_streams <input> reports the following:

 {{{
 [STREAM]
 index=1
 codec_name=dca
 codec_long_name=DCA (DTS Coherent Acoustics)
 profile=DTS
 codec_type=audio
 codec_time_base=1/48000
 codec_tag_string=[0][0][0][0]
 codec_tag=0x0000
 sample_fmt=s32p
 sample_rate=48000
 channels=6
 channel_layout=5.1(side)
 bits_per_sample=0
 id=N/A
 r_frame_rate=0/0
 avg_frame_rate=0/0
 time_base=1/1000
 start_pts=0
 start_time=0.000000
 duration_ts=N/A
 duration=N/A
 bit_rate=1536000
 max_bit_rate=N/A
 bits_per_raw_sample=24
 nb_frames=N/A
 nb_read_frames=N/A
 nb_read_packets=N/A
 DISPOSITION:default=1
 DISPOSITION:dub=0
 DISPOSITION:original=0
 DISPOSITION:comment=0
 DISPOSITION:lyrics=0
 DISPOSITION:karaoke=0
 DISPOSITION:forced=1
 DISPOSITION:hearing_impaired=0
 DISPOSITION:visual_impaired=0
 DISPOSITION:clean_effects=0
 DISPOSITION:attached_pic=0
 TAG:language=ger
 TAG:title=DTS 5.1 @ 1509/768 Kbps
 [/STREAM]
 [STREAM]
 index=2
 codec_name=dca
 codec_long_name=DCA (DTS Coherent Acoustics)
 profile=DTS-HD MA
 codec_type=audio
 codec_time_base=1/48000
 codec_tag_string=[0][0][0][0]
 codec_tag=0x0000
 sample_fmt=s32p
 sample_rate=48000
 channels=6
 channel_layout=5.1(side)
 bits_per_sample=0
 id=N/A
 r_frame_rate=0/0
 avg_frame_rate=0/0
 time_base=1/1000
 start_pts=0
 start_time=0.000000
 duration_ts=N/A
 duration=N/A
 bit_rate=N/A
 max_bit_rate=N/A
 bits_per_raw_sample=24
 nb_frames=N/A
 nb_read_frames=N/A
 nb_read_packets=N/A
 DISPOSITION:default=0
 DISPOSITION:dub=0
 DISPOSITION:original=0
 DISPOSITION:comment=0
 DISPOSITION:lyrics=0
 DISPOSITION:karaoke=0
 DISPOSITION:forced=0
 DISPOSITION:hearing_impaired=0
 DISPOSITION:visual_impaired=0
 DISPOSITION:clean_effects=0
 DISPOSITION:attached_pic=0
 TAG:language=eng
 TAG:title=~ DTS-HD MA 5.1 @ 24bit
 [/STREAM]
 }}}

 Notice especially "bits_per_sample=0" and "sample_fmt=s32p".

 This is a bug very similar to this one (I think):
 https://trac.ffmpeg.org/ticket/3919


 == Why is this an issue? ==
 Because when I try to convert these audio streams to ac3, ffmpeg creates a
 32 bit audio stream which is a waste of space. More details can be found
 here: http://ffmpeg.gusari.org/viewtopic.php?f=11&t=2705


 == How to reproduce: ==
 Unfortunately, I can't send you my audio streams, because these are from a
 copyright protected movie. But maybe you can just grab any blu ray movie
 with 24 bit DTS audio stream and try if you can reproduce the issue. If
 you want me to try any specific command or something on my files, just let
 me know.

 ffmpeg version 3.0 Win64,
 [http://ffmpeg.zeranoe.com/builds/win64/static/ffmpeg-3.0-win64-static.7z
 this one].

--
Ticket URL: <https://trac.ffmpeg.org/ticket/5282>
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