howto remove meta info about MP4 or FLV file downloaded off Youtube?

UNIX for Advanced & Expert Users
1

Hi

I tried a tool called mediainfo

> brew info  media-info
media-info 0.7.51
http://mediainfo.sourceforge.net
Depends on: pkg-config
/usr/local/Cellar/media-info/0.7.51 (3 files, 14M)
http://github.com/mxcl/homebrew/commits/master/Library/Formula/media-info.rb

Got details from a test file. Was surprised that I can see so much meta info.

> mediainfo test.mp4 
General
Complete name                            : test.mp4
Format                                   : MPEG-4
Format profile                           : Base Media / Version 2
Codec ID                                 : mp42
File size                                : 27.6 MiB
Duration                                 : 1mn 14s
Overall bit rate mode                    : Variable
Overall bit rate                         : 3 106 Kbps
Encoded date                             : UTC 2011-06-12 15:16:43
Tagged date                              : UTC 2011-06-12 15:16:43
gsst                                     : 0
gstd                                     : 74696
gssd                                     : BC1F7C107MM1321292341565026
gshh                                     : o-o.preferred.vadafone-zrh1.v20.lscache3.c.youtube.com

Video
ID                                       : 1
Format                                   : AVC
Format/Info                              : Advanced Video Codec
Format profile                           : High@L3.1
Format settings, CABAC                   : Yes
Format settings, ReFrames                : 1 frame
Codec ID                                 : avc1
Codec ID/Info                            : Advanced Video Coding
Duration                                 : 1mn 14s
Bit rate                                 : 2 948 Kbps
Maximum bit rate                         : 4 516 Kbps
Width                                    : 1 280 pixels
Height                                   : 720 pixels
Display aspect ratio                     : 16:9
Frame rate mode                          : Variable
Frame rate                               : 23.537 fps
Minimum frame rate                       : 23.256 fps
Maximum frame rate                       : 83.333 fps
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bits
Scan type                                : Progressive
Bits/(Pixel*Frame)                       : 0.136
Stream size                              : 26.2 MiB (95%)
Tagged date                              : UTC 2011-06-12 15:16:43

Audio
ID                                       : 2
Format                                   : AAC
Format/Info                              : Advanced Audio Codec
Format profile                           : LC
Codec ID                                 : 40
Duration                                 : 1mn 14s
Bit rate mode                            : Variable
Bit rate                                 : 152 Kbps
Maximum bit rate                         : 187 Kbps
Channel(s)                               : 2 channels
Channel positions                        : Front: L R
Sampling rate                            : 44.1 KHz
Compression mode                         : Lossy
Stream size                              : 1.35 MiB (5%)
Title                                    : IsoMedia File Produced by Google, 5-11-2011
Encoded date                             : UTC 2011-06-12 15:16:43
Tagged date                              : UTC 2011-06-12 15:16:43

What does this exactly mean? Why here is my provider named Vadafone?

gsst                                     : 0
 gstd                                     : 74696
 gssd                                     : BC1F7C107MM1321292341565026
 gshh                                     : o-o.preferred.vadafone-zrh1.v20.lscache3.c.youtube.com

Howto clear or edit those meta info?

I am running Mac OS X Lion

2

Try exiftool.

3

doesn't work Error: Writing of MP4 files is not yet supported

> exiftool -exif:all= test.mp4 
Error: Writing of MP4 files is not yet supported - test.mp4
    0 image files updated
    1 files weren't updated due to errors

exiftool even doesn't show all tags

> exiftool -all test.mp4 
ExifTool Version Number         : 8.71
File Name                       : test.mp4
Directory                       : .
File Size                       : 25 MB
File Modification Date/Time     : 2011:12:03 21:01:45+01:00
File Permissions                : rw-r--r--
File Type                       : MP4
MIME Type                       : video/mp4
Major Brand                     : MP4 v2 [ISO 14496-14]
Minor Version                   : 0.0.0
Compatible Brands               : isom, mp42
Movie Header Version            : 0
Create Date                     : 2011:12:02 03:45:58
Modify Date                     : 2011:12:02 03:45:58
Time Scale                      : 600
Duration                        : 0:02:17
Preferred Rate                  : 1
Preferred Volume                : 100.00%
Preview Time                    : 0 s
Preview Duration                : 0 s
Poster Time                     : 0 s
Selection Time                  : 0 s
Selection Duration              : 0 s
Current Time                    : 0 s
Next Track ID                   : 3
Track Header Version            : 0
Track Create Date               : 0000:00:00 00:00:00
Track Modify Date               : 2011:12:02 03:45:58
Track ID                        : 1
Track Duration                  : 0:02:17
Track Layer                     : 0
Track Volume                    : 0.00%
Image Width                     : 1460
Image Height                    : 1080
Graphics Mode                   : srcCopy
Op Color                        : 0 0 0
Compressor ID                   : avc1
Source Image Width              : 1460
Source Image Height             : 1080
X Resolution                    : 72
Y Resolution                    : 72
Bit Depth                       : 24
Video Frame Rate                : 10
Matrix Structure                : 1 0 0 0 1 0 0 0 1
Media Header Version            : 0
Media Create Date               : 2011:12:02 03:45:58
Media Modify Date               : 2011:12:02 03:45:58
Media Time Scale                : 44100
Media Duration                  : 0:02:17
Media Language Code             : und
Handler Description             : IsoMedia File Produced by Google, 5-11-2011
Balance                         : 0
Audio Format                    : mp4a
Audio Channels                  : 2
Audio Bits Per Sample           : 16
Audio Sample Rate               : 44100
Handler Type                    : Metadata
Handler Vendor ID               : Apple
Movie Data Size                 : 25906609
Avg Bitrate                     : 1.51 Mbps
Image Size                      : 1460x1080
Rotation                        : 0

not show by exiftool (but by mediainfo):

gshh : o-o.preferred.vadafone-zrh1.v20.lscache3.c.youtube.com

4

Thank you Roger Howard <rogerhoward@gmail.com>