[MPlayer-users] debian wmv Video used to play but Doesn't now.

[Mike Hodson]

On Wed, Sep 12, 2018 at 12:58 PM stan <gyvoy at q.com> wrote:

> > On Wed, 12 Sep 2018 12:22:35 -0500
> > "Martin McCormick" <martin.m at suddenlink.net> wrote:
>
> >       I have a file that I first acquired in 2006 called kosovo.wmv.


Martin, you do you have the .WMV file locally, correct?

"Listed on youtube" implies that indeed, Youtube themselves have converted
the file.
Interestingly enough, to 44.1khz for AAC audio, and by default Opus is
48khz due to its spec.

mediainfo has the following to say about the AAC audio after a manual
download with youtube-dl -f 133+140
Audio
ID                                       : 2
Format                                   : AAC
Format/Info                              : Advanced Audio Codec
Format profile                           : LC
Codec ID                                 : 40
Duration                                 : 1mn 5s
Bit rate mode                            : Variable
Bit rate                                 : 93.6 Kbps
Channel(s)                               : 2 channels
Channel(s)_Original                      : 1 channel
Channel positions                        : Front: C
Sampling rate                            : 44.1 KHz
Compression mode                         : Lossy
Stream size                              : 744 KiB (27%)
Encoded date                             : UTC 2014-02-26 00:20:22
Tagged date                              : UTC 2014-02-26 00:20:22

and about the Opus audio:
Audio
ID                                       : 2
Format                                   : Opus
Codec ID                                 : A_OPUS
Duration                                 : 1mn 5s
Channel(s)                               : 1 channel
Channel positions                        : Front: C
Sampling rate                            : 48.0 KHz
Compression mode                         : Lossy
Delay relative to video                  : -7ms
Language                                 : English
Default                                  : Yes
Forced                                   : No


This test is at best wrong, and at worst altogether misleading if someone
doesn't understand the mechanics behind youtube ingesting a video means the
original audio and video just get eaten up, and new data entirely spat out,
at different samplerates, and file formats.  Apparently nothing but the
video dimensions of 320x240 were retained.


> I tried grabbing kosovo.wmv with youtube-dl, it complained that the
> sound format wasn't compatible with the video, and performed a
> transformation, so it probably isn't a good test.


Stan, What ended up happening, is that youtube-dl by default ended up
choosing the Opus audio, with the MP4 video. Why, I'm not 100% sure.  In
this case, MKV is used to re-multiplex non-similar-codec bitstreams into 1
file, as MKV does not care that "Mpeg codecs should go with mpeg codecs,
Opus and Vp9 should be together" MKV just contains them, and keeps a codec
label on the stream so the decoder can do what it needs to with the file.

Indeed the test is wholly invalid for reasons outlined above in reply to
Martin's part of this double-reply.

What is actually cared about is the actual WMV format file, that presently
seems to only exist on Martin's local system.

Mike