Opened 8 years ago
Closed 4 years ago
#12728 closed Bug Report - General (Unverified)
Mythtranscode reporting incorrect audio properties
Reported by: | Owned by: | JYA | |
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Priority: | minor | Milestone: | unknown |
Component: | MythTV - Mythtranscode | Version: | 0.27.6 |
Severity: | medium | Keywords: | mythtranscode audio |
Cc: | Ticket locked: | no |
Description
I have a recording I am trying to transcode lossless to strip commercials. From there, I will re-encode using HandBrake?.
The original recording's audio is reported thusly (via mediainfo)
Audio #1 ID : 6302 (0x189E) Menu ID : 1 (0x1) Format : AC-3 Format/Info : Audio Coding 3 Mode extension : CM (complete main) Format settings, Endianness : Big Codec ID : 129 Duration : 35mn 58s Bit rate mode : Constant Bit rate : 384 Kbps Channel(s) : 6 channels Channel positions : Front: L C R, Side: L R, LFE Sampling rate : 48.0 KHz Bit depth : 16 bits Compression mode : Lossy Delay relative to video : -562ms Stream size : 98.8 MiB (2%) Language : English
I use mythtranscode from the CLI, and created the transcoded video thusly:
mythtranscode --chanid 1577 --starttime 20160327135900 --mpeg2 --honorcutlist -e ts --passthrough -o ~/tmp/myrecording.mpg
The audio of the resultant file (mediainfo):
Audio #1 ID : 4301 (0x10CD) Menu ID : 1 (0x1) Format : AC-3 Format/Info : Audio Coding 3 Mode extension : CM (complete main) Format settings, Endianness : Big Codec ID : 129 Duration : 24mn 29s Bit rate mode : Constant Bit rate : 192 Kbps Channel(s) : 2 channels Channel positions : Front: L R Sampling rate : 48.0 KHz Bit depth : 16 bits Compression mode : Lossy Delay relative to video : 8ms Stream size : 33.6 MiB (1%) Language : English
Note the Channel(s) are reduced from 6 to 2, and the 'Bit rate' reduced to 192Bkps from 384Kbps.
This is, however, incorrect. Playing the transcoded file with VLC shows:
Type: Audio Original ID: 4301 Codec: A52 Audio (aka AC3)(a52 ) Language: Englisg Channels: 3F2R/LFE Sample rate: 48000 Hz Bitrate: 384 kb/s
Note that it IS actually 6 channel, 384Kbps. So the audio of the file is correct, but the descriptors in the TS container are incorrect.
Unfortunately, when I open the transcoded file with HandBrake?, HandBrake? reports that the source audio is only 2 channel, and therefore cannot transcode to, e.g. AAC 6 channel; only 2.
Attachments (1)
Change History (2)
Changed 8 years ago by
Attachment: | mythtranscode_version.txt added |
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comment:1 Changed 4 years ago by
Resolution: | → Unverified |
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Status: | new → closed |
Closing all old tickets in trac.
If your issue still persists, please open an issue in Github https://github.com/MythTV/mythtv/issues
and reference the existing trac ticket.
output of mythtranscode --version