MKV that starts as stereo but switches to 5.1, only plays stereo?

WD Legacy Products WD TV Live & Live Plus
1

I have some .MKVs that for the first two minutes of the stream, the audio is a 2Ch signal.  After that, it is AC3 5.1.  For some reason however, the WDTV only plays it as stereo throughout.  Is there something I am doing wrong, or something I can adjust with the file to make it play the 5.1?

Thanks.

2

Please post the full TEXT output of MEDIAINFO for such a file.

http://mediainfo.sourceforge.net

3

General
Unique ID                        : 230369465152351350116235453513638344092 (0xAD4F8B8D0BBB5A4ABA3343E91897F59C)
Complete name                    : test.mkv
Format                           : Matroska
File size                        : 2.36 GiB
Duration                         : 57mn 26s
Overall bit rate                 : 5 884 Kbps
Movie name                       : test.mkv 15297
Encoded date                     : UTC 2011-04-26 07:51:19
Writing application              : mkvmerge v4.6.0 (‘Still Crazy After All These Years’) built on Mar 10 2011 02:50:32
Writing library                  : libebml v1.2.0 + libmatroska v1.1.0

Video
ID                               : 1
Format                           : AVC
Format/Info                      : Advanced Video Codec
Format profile                   : High@L4.1
Format settings, CABAC           : Yes
Format settings, ReFrames        : 9 frames
Muxing mode                      : Header stripping
Codec ID                         : V_MPEG4/ISO/AVC
Duration                         : 57mn 26s
Bit rate                         : 5 500 Kbps
Width                            : 1 280 pixels
Height                           : 714 pixels
Display aspect ratio             : 16:9
Frame rate                       : 23.976 fps
Color space                      : YUV
Chroma subsampling               : 4:2:0
Bit depth                        : 8 bits
Scan type                        : Progressive
Bits/(Pixel*Frame)               : 0.251
Stream size                      : 2.16 GiB (91%)
Writing library                  : x264 core 115 r1936 7a9e08d
Encoding settings                : cabac=1 / ref=9 / deblock=1:-3:-3 / analyse=0x3:0x133 / me=tesa / subme=10 / psy=1 / psy_rd=1.10:0.10 / mixed_ref=1 / me_range=32 / chroma_me=1 / trellis=2 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=0 / chroma_qp_offset=-3 / threads=8 / sliced_threads=0 / nr=0 / decimate=0 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=12 / b_pyramid=2 / b_adapt=2 / b_bias=0 / direct=3 / weightb=1 / open_gop=0 / weightp=2 / keyint=250 / keyint_min=23 / scenecut=40 / intra_refresh=0 / rc=2pass / mbtree=0 / bitrate=5500 / ratetol=1.0 / qcomp=0.70 / qpmin=0 / qpmax=69 / qpstep=4 / cplxblur=20.0 / qblur=0.5 / ip_ratio=1.40 / pb_ratio=1.30 / aq=2:0.60
Language                         : English

Audio
ID                               : 2
Format                           : AC-3
Format/Info                      : Audio Coding 3
Mode extension                   : CM (complete main)
Muxing mode                      : Header stripping
Codec ID                         : A_AC3
Duration                         : 57mn 26s
Bit rate mode                    : Constant
Bit rate                         : 384 Kbps
Channel(s)                       : 2 channels
Channel positions                : Front: L R
Sampling rate                    : 48.0 KHz
Bit depth                        : 16 bits
Compression mode                 : Lossy
Stream size                      : 158 MiB (7%)

4

I notice that it states that it is 2.0, but I am wondering if that is because it starts out as such.

5

If it says 2.0 then that is what it is.

Never heard of an audio stream that can change the number of channels.

6

Yeah, it can be done… Like recorded TV, commercials are usually 2.0 but the main program is 5.1. I’m not sure how MediaInfo reports on that, or if MKV can do it.

7

What about another format?  Maybe I can demux it and do something else with it?