#! /bin/sh # cat << EOF_1 Content-type: text/html
H.263/Pyramid Decoder

Welcome to the ScalVico H.263+Pyramid page

The decoder has been implemented as a Netscape plugin but it is also available as a standalone application. Both have been compiled for Solaris platforms. To find out, if your browser already knows about the decoder plugin check your "help->About Plugins" list. If not, first download the plugin or the standalone application (we recommend to use the plugin).

View some standard test sequences

Bandwidth:
Modem ISDN High 		Display:
Large Small
Audio:
On Off 		Speed:
Fast Real Slow

EOF_1 suff=hpy sdir=Streams for i in $sdir/*.0.$suff; do test -z "$c" && echo "" c="X$c" test "$c" = "XX" && c= ri=`basename $i .0.$suff` ci=$sdir.cgi/$ri.$suff im=../images/$ri.jpg test -f $im || im=../images/film.gif echo "
" echo "    " done echo "
" cat << EOF_2

These sequences are coded with three layers, using datarates suitable for transmission over modems, ISDN and high quality internet channels. The modem layer is coded with H.263 in QCIF quality. The bitrate for the videostream is 18 kbps. Thus, 10.8 kbps are still open for audio and additional information.
For ISDN one pyramid layer (using lattice vector quantization; QCIF) is added, such that the overall bitrate for video is below 50 kbps. Thus, 14 kbps are still open for audio and additional information. The bitrate for the high quality CIF layer is between 150 kbps and 1Mbps, depending on the sequence.

Approximatly every second one frame is coded in INTRA modus in each layer to allow random access and recovery from transmission errors in future releases.
For error resilience we have added header for the GOBs (Group-of-blocks) in the H.263 as well as in the pyramid layer.

At the moment only transmission over HTTP/TCP/IP connections is possible. However, we are working on the extension to RTP/UDP transmission, which will be available soon. EOF_2 exit 0