VideoNow Format -- By GregSmith
The VideoNow player is little more than a modified CD Player.  The disks are 3.5" in diamater (just 0.25" larger than a standard Mini-CDR).  The extra media is to support a full 30 minutes of video.

The files stored on the disks appear to be ordinary CD tracks, but the data inside is not digitized music, but digitized audio and video.  The format of the files is proprietary (you wont find a CODEC for VideoNow on the Internet - well at least not as of 10/30/2003-though PVDTools includes a programs that can be used to extract audio and video).  It is not a complicated format.  I have dubbed this format VideoNow CD or VNCD format.

The right channel is the audio track and the left channel is the video track. They are 16-bits per channel at 44100 samples per second.



The right track is an interleaved track of 8-bit audio and some other information that appears to be synchronization data. 

The left channel information is organized as 147 rows of 40 bytes. (40 bytes makes for 80 pixels of greyscale, 4 bits per pixel making 16 shades of gray). 80 of the rows are actual data to be displayed. The remaing 67 rows are filled with regular values (like 0xe1e1).  The extra data is merely padding to sync the sound with the video.

Numerically, there are 147*40 = 5880 bytes per frame. If you divide the audio rate (44100 samples/second) by 5880 you get 7.5 frames per second. and considering that there are 2 bytes per sample you multiply it by 2 to get 15 frames per second.



For some reason the VNCD video portion starts with 6402 bytes of nearly blank info.



5062 bytes of zeroes

1340 bytes of 0xe1



each frame is composed of 40*147 bytes

40 bytes per row

80 rows per image

67 rows of "random" info.

---------------------------

1340 bytes of 0xe1

3200 bytes of video data (40 x 80)

1340 bytes of 0xd2

------

5880 bytes per frame



The audio track is also preceeded by 2531 bytes of 0x00. Note that this is precisely 1/2 the number of bytes of the video header's 0x00s.  Remember that the audio track is composed of 8-bit values for the audio and some sync data? Well the sync data is a constant stream of 0x5a.