<div><BR>Hi, <STRONG><EM>jp_liu </EM></STRONG></div> <div> </div> <div>For avcC, the data struct is "len + data", no matter sps, pps or nal, so data could be parsed out from "len" information.</div> <div><BR>"codec_data" contains sps and pps.<BR>qtdemux send h264 data by means of frame, which may contains several nals, they are all formated as "len + data".<BR>They are translated as bitstreams.</div> <div>please check ffmpeg.</div> <div> </div> <div>Thanks <BR><BR><B><I>jp_liu <jp_liu@astrocom.cn></I></B> 写道：</div> <BLOCKQUOTE class=replbq style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #1010ff 2px solid"> <META content="KsDHTMLEDLib.ocx, FreeWare HTML Editor 1.164.2, ?Kurt Senfer" name=GENERATOR> <DIV>zhangfei gao, Hello </DIV> <DIV> </DIV> <DIV>My h264 decoder support say that:</DIV> <DIV>I believe MP4 uses the NAL format (Need to confirm) and hence doesn’t have the NAL Start codes. One needs to convert that to bytstream format because our decoders support only byte-stream format. Also one needs to do this while demuxing it from MP4 otherwise the information various slice positions would be lost. </DIV> <DIV> </DIV> <DIV>So, How should I do?</DIV> <DIV> </DIV> <DIV>jp_liu, <A href="mailto:jp_liu@astrocom.cn">jp_liu@astrocom.cn</A></DIV> <DIV>2007-03-26 </DIV> <BLOCKQUOTE style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px"> <DIV style="FONT-WEIGHT: normal; FONT-SIZE: 9pt; LINE-HEIGHT: normal; FONT-STYLE: normal; FONT-VARIANT: normal">----- Receiving the following content ----- </DIV> <DIV style="FONT-WEIGHT: normal; FONT-SIZE: 9pt; BACKGROUND: #e4e4e4; LINE-HEIGHT: normal; FONT-STYLE: normal; FONT-VARIANT: normal; font-color: black"><B>From:</B> <A href="mailto:gaozhangfei@yahoo.com.cn">zhangfei gao</A> </DIV> <DIV style="FONT-WEIGHT: normal; FONT-SIZE: 9pt; LINE-HEIGHT: normal; FONT-STYLE: normal; FONT-VARIANT: normal"><B>Receiver:</B> <A href="mailto:gstreamer-devel@lists.sourceforge.net">gstreamer-devel</A> </DIV> <DIV style="FONT-WEIGHT: normal; FONT-SIZE: 9pt; LINE-HEIGHT: normal; FONT-STYLE: normal; FONT-VARIANT: normal"><B>Time:</B> 2007-03-22, 21:24:01</DIV> <DIV style="FONT-WEIGHT: normal; FONT-SIZE: 9pt; LINE-HEIGHT: normal; FONT-STYLE: normal; FONT-VARIANT: normal"><B>Subject:</B> [gst-devel]re： Re: how to use qtdemux to demux h264 stream from MP4?</DIV> <DIV><BR></DIV> <DIV></DIV> <DIV></DIV> <DIV> <DIV>hi, jp_liu</DIV> <DIV> </DIV> <DIV>"h264.c" in ffmpeg has useful information of how to parse "codec_data" which get set_caps.</DIV> <DIV>"codec_data" has all the nal_length, sps data and pps data.</DIV> <DIV> </DIV> <DIV>Thanks<BR><B><I>Jan Schmidt <thaytan@noraisin.net></I></B> 写道：</DIV> <BLOCKQUOTE class=replbq style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #1010ff 2px solid">jp_liu wrote:<BR>> Hello, gstreamer-devel<BR>> <BR>> How to use qtdemux to demux h264 stream from MP4?<BR>> The demuxed h264 stream looks have no startcodes before every NAL<BR>> Unit. So, Some key information ( such as: SPS PPS ....) is missed. It<BR>> caused my H264 decoder can not decode the frame which demuxed by qtdemux .<BR>> How can I solve this problem?<BR>> <BR><BR>I think the information your decoder is looking for is the stuff<BR>provided by the 'codec_data' in the caps. This is the header information<BR>that quicktime stores and provides separately from the actual data stream.<BR><BR>Regards,<BR>Jan.<BR><BR>-------------------------------------------------------------------------<BR>Take Surveys. Earn Cash. Influence the Future of IT<BR>Join SourceForge.net's Techsay panel and you'll get the chance to share your<BR>opinions on IT & business topics through brief surveys-and earn cash<BR>http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV_______________________________________________<BR>gstreamer-devel mailing list<BR>gstreamer-devel@lists.sourceforge.net<BR>https://lists.sourceforge.net/lists/listinfo/gstreamer-devel<BR></BLOCKQUOTE><BR> <div> <HR SIZE=1> <A href="http://cn.mail.yahoo.com/" target=blank>抢注雅虎免费邮箱-3.5G容量，20M附件！</A> </DIV></BLOCKQUOTE></BLOCKQUOTE><BR><p>  <hr size=1><a href="http://music.yahoo.com.cn/?source=mail_mailbox_footer" target=blank> Mp3疯狂搜-新歌热歌高速下 </a>