What is this "wvm" file, and can I get rid of it? I have a Nexus 7 running Jelly Bean. Using the Android File Transfer program, I was examining the contents of part of the internal drive and found this:

/Android/data/com.google.android.videos/files/Movies/bWF0dGhldy5ob2x0QGdtYWlsLmNvbQ/framework_LFL4UnYvaGE.wvm (2.82 GB, last modified 18 Jul 2012, 7:59 PM)

In another directory (adjacent to bWF0dGhldy5ob2x0QGdtYWlsLmNvbQ), there's a subtitles directory which contains two files:

LFL4UnYvaGE.cc (264 bytes) and LFL4UnYvaGE.en.cc (129 KB), both modified on the same day (18 Jul, but earlier in the day at 5:57 PM).



As you can see, the .wvm file is very large. I tried renaming its parent Movies folder to Movies2 to see if it broke anything and so far it doesn't seem to matter. I tried copying it to my Mac but it says it is unable to copy the file (yet it can copy the parent folder(s) okay). And I don't currently have any movies (that I know of) saved to my tablet either from the Play store or copied over from my computer.

What does this file do, and would it be safe to delete it (and the associated subtitles) to save space?
These files are for the Transformers: Dark of the Moon film which was included promotionally with your Nexus 7.  The movie was not, at least in my case, pre-installed on your device, as it takes a considerable amount of your available storage space (especially if you have an 8GB unit!).

I'm guessing you must at some point have unknowingly hit the small 'button' on the video telling it to download the film for offline use.



The first thing that came to my mind was, that this may be a WebM video file (Matroska container + VP8 video stream + Vorbis audio stream). It would have made sense. But feeding the file to MediaInfo looks like this:

$ mediainfo Downloads/framework_BpAYRcyW2_A.wvm
General
Complete name                            : Downloads/framework_BpAYRcyW2_A.wvm
Format                                   : MPEG-PS
File size                                : 2.73 GiB
Duration                                 : 2h 34mn
Overall bit rate                         : 2 532 Kbps

Video
ID                                       : 224 (0xE0)
Format                                   : AVC
Format/Info                              : Advanced Video Codec
Format profile                           : Main@L3.1
Format settings, CABAC                   : Yes
Format settings, ReFrames                : 3 frames
Duration                                 : 2h 34mn
Width                                    : 1 280 pixels
Height                                   : 536 pixels
Display aspect ratio                     : 2.40:1
Frame rate mode                          : Variable
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bits
Scan type                                : Progressive

Audio
ID                                       : 192 (0xC0)
Format                                   : AAC
Format/Info                              : Advanced Audio Codec
Format version                           : Version 4
Format profile                           : LC
Muxing mode                              : ADTS
Duration                                 : 2h 34mn
Bit rate mode                            : Variable / Variable / Variable
Minimum bit rate                         : 190 Kbps / 190 Kbps
Maximum bit rate                         : 231 Kbps / 231 Kbps
Channel(s)                               : 2 channels
Channel positions                        : Front: L R
Sampling rate                            : 44.1 KHz
Compression mode                         : Lossy

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An AVC video stream and AAC audio stream, is what one would expect from a regular MP4, but MPEG-PS format (PS = program stream) is unusual. This is how a regular MP4 looks in MediaInfo:

$ mediainfo .miro/Movies/FLOSS-Weekly/floss0222_h264m_864x480_500.mp4 
General
Complete name                            : .miro/Movies/FLOSS-Weekly/floss0222_h264m_864x480_500.mp4
Format                                   : MPEG-4
Format profile                           : Base Media
Codec ID                                 : isom
File size                                : 282 MiB
Duration                                 : 1h 5mn
Overall bit rate mode                    : Variable
Overall bit rate                         : 605 Kbps
Writing application                      : Lavf54.3.100

Video
ID                                       : 1
Format                                   : AVC
Format/Info                              : Advanced Video Codec
Format profile                           : Main@L3.1
Format settings, CABAC                   : Yes
Format settings, ReFrames                : 4 frames
Codec ID                                 : avc1
Codec ID/Info                            : Advanced Video Coding
Duration                                 : 1h 5mn
Bit rate                                 : 500 Kbps
Width                                    : 864 pixels
Height                                   : 480 pixels
Display aspect ratio                     : 16:9
Frame rate mode                          : Constant
Frame rate                               : 29.970 fps
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bits
Scan type                                : Progressive
Bits/(Pixel*Frame)                       : 0.040
Stream size                              : 233 MiB (83%)
Writing library                          : x264 core 120 r2164 da19765
Encoding settings                        : cabac=1 / ref=2 / deblock=1:0:0 / analyse=0x1:0x131 / me=umh / subme=6 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=1 / 8x8dct=0 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-2 / threads=12 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=2 / b_pyramid=2 / b_adapt=1 / b_bias=0 / direct=1 / weightb=1 / open_gop=0 / weightp=2 / keyint=60 / keyint_min=31 / scenecut=0 / intra_refresh=0 / rc_lookahead=40 / rc=2pass / mbtree=1 / bitrate=500 / ratetol=1.0 / qcomp=0.60 / qpmin=0 / qpmax=51 / qpstep=4 / cplxblur=20.0 / qblur=0.5 / vbv_maxrate=1500 / vbv_bufsize=6000 / nal_hrd=none / ip_ratio=1.40 / aq=1:1.00
Language                                 : English

Audio
ID                                       : 2
Format                                   : AAC
Format/Info                              : Advanced Audio Codec
Format profile                           : LC
Codec ID                                 : 40
Duration                                 : 1h 5mn
Bit rate mode                            : Variable
Bit rate                                 : 96.0 Kbps
Maximum bit rate                         : 1 500 Kbps
Channel(s)                               : 2 channels
Channel positions                        : Front: L R
Sampling rate                            : 48.0 KHz
Compression mode                         : Lossy
Stream size                              : 44.7 MiB (16%)
Language                                 : English


The file [from the Nexus 7] even  plays for a few seconds in VLC and in MPlayer, but then I get error messages. So either the format is not yet supported or it's sort of encrypted.