title: 3GP video with "jpeg" video codec
body: <p>I have cheap feature phone which can record videos in 3gp file format. When I upload such video to computer and inspect it with mediainfo it gives mysteriuos output:</p>
  <pre><code>Format                                   : MPEG-4
  Format profile                           : 3GPP Media Release 5
  Codec ID                                 : 3gp5 (3gp5)
  File size                                : 4.69 MiB
  Duration                                 : 1 min 7 s
  Overall bit rate                         : 585 kb/s
  Encoded date                             : UTC 1970-01-01 00:02:13
  Tagged date                              : UTC 1970-01-01 00:02:13
  
  Video
  ID                                       : 2
  Format                                   : JPEG
  Codec ID                                 : jpeg
  Duration                                 : 1 min 7 s
  Source duration                          : 1 min 7 s
  Bit rate                                 : 571 kb/s
  Width                                    : 240 pixels
  Height                                   : 320 pixels
  Display aspect ratio                     : 0.750
  Frame rate mode                          : Variable
  Frame rate                               : 9.137 FPS
  Minimum frame rate                       : 3.686 FPS
  Maximum frame rate                       : 17.192 FPS
  Color space                              : YUV
  Chroma subsampling                       : 4:2:2
  Bit depth                                : 8 bits
  Compression mode                         : Lossy
  Bits/(Pixel*Frame)                       : 0.813
  Stream size                              : 4.57 MiB (97%)
  Source stream size                       : 4.57 MiB (97%)
  Language                                 : English
  Encoded date                             : UTC 1970-01-01 00:02:13
  Tagged date                              : UTC 1970-01-01 00:02:13
  mdhd_Duration                            : 67133
  </code></pre>
  <p>The video codec is &quot;JPEG&quot;.
  When I play video in Totem Video Player, codec name is &quot;JPEG still images&quot;.
  I tested that my phone doesn't support MJPEG and mediainfo shows that codec is (also) identified as MPEG-4. When I opened video in hex editor it appeared as sequences of JPEG images, which shouldn't be possible (3gp container supports H.263 and MPEG-4 not MJPEG). On the other hand sample video converted to 3gp MPEG-4 gives this mediainfo output:</p>
  <pre><code>Format profile                           : 3GPP Media Release 4
  Codec ID                                 : 3gp4 (isom/iso2/3gp4)
  File size                                : 1.84 MiB
  Duration                                 : 16 s 50 ms
  Overall bit rate mode                    : Variable
  Overall bit rate                         : 960 kb/s
  
  Video
  ID                                       : 1
  Format                                   : MPEG-4 Visual
  Format profile                           : Simple@L3
  Format settings, BVOP                    : No
  Format settings, QPel                    : No
  Format settings, GMC                     : No warppoints
  Format settings, Matrix                  : Default (H.263)
  Codec ID                                 : mp4v-20
  Duration                                 : 16 s 50 ms
  Bit rate mode                            : Variable
  Bit rate                                 : 659 kb/s
  Maximum bit rate                         : 1 000 kb/s
  Width                                    : 240 pixels
  Height                                   : 180 pixels
  Display aspect ratio                     : 16:9
  Frame rate mode                          : Constant
  Frame rate                               : 20.000 FPS
  Color space                              : YUV
  Chroma subsampling                       : 4:2:0
  Bit depth                                : 8 bits
  Scan type                                : Progressive
  Compression mode                         : Lossy
  Bits/(Pixel*Frame)                       : 0.763
  Stream size                              : 1.26 MiB (69%)
  Title                                    : ISO Media file produced by Google Inc.
  Writing library                          : XviD 69
  </code></pre>
  <p>So as you can see technically it is also MPEG-4. Totem identifies this second video as MPEG-4.
  Second video is playable on my phone.
  My question is how can I make/encode my own 3gp video with &quot;jpeg&quot; video codec?
  Chipset of my phone is sc6531e (datasheet is avaliable in internet)</p>