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<p class="MsoNormal">Hi,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I am trying to implement decoding of H264 NAL units that are received from the camera (using live555 rtsp streaming). Everything works fine if received NAL unit is IDR (see part of the code in PS) but it does not work for SLICE NAL unit
(nal_unit_type == 1). To decode image this NAL unit is not enough on its own and reference needs to be made to all the units since last IDR unit (key frame with nal_unit_type == 5). I do not know how to implement this.
<span style="color:#1F497D"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:black">How to combine last IDR unit with the following SLICE NAL units to produce H264 frame before sending it to the decoder?<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D;mso-fareast-language:EN-GB"><img width="468" height="94" id="Picture_x0020_3" src="cid:image003.png@01CF8C74.58C38FA0"></span><span style="color:#1F497D"><o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Can you give me any advice or point me to the right direction?<span style="color:#1F497D">
</span>Any help is greatly appreciated.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Regards,<o:p></o:p></p>
<p class="MsoNormal">Miladin<o:p></o:p></p>
<p class="MsoNormal" style="text-autospace:none"><span style="color:black;background:white;mso-highlight:white"><o:p> </o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="color:black;background:white;mso-highlight:white">PS.<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="color:#1F497D;background:white;mso-highlight:white"><o:p> </o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="color:black;background:white;mso-highlight:white">Content of the buffer sent to the H264 decoder that gets decoded properly.<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas;color:#1F497D;background:white;mso-highlight:white"><o:p> </o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="color:#1F497D;mso-fareast-language:EN-GB"><img width="741" height="91" id="Picture_x0020_1" src="cid:image001.png@01CF8C73.13092D90"></span><span style="color:#1F497D;background:white;mso-highlight:white"><o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="color:#1F497D;background:white;mso-highlight:white"><o:p> </o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas;color:black">unsigned char strTmp[4] = { 0, 0, 0, 1 };<span style="background:white;mso-highlight:white"><o:p></o:p></span></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas;color:black;background:white;mso-highlight:white"><o:p> </o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas;color:black;background:white;mso-highlight:white">// getting SPS config info<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas;color:black;background:white;mso-highlight:white">memcpy(acSPS, strTmp, 4);<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas;color:black;background:white;mso-highlight:white">memcpy(&acSPS[4], m_pcRtspStream->m_ustrSPS, m_pcRtspStream->m_iSPSLen);<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas;color:black;background:white;mso-highlight:white">nSPSLength = m_pcRtspStream->m_iSPSLen + 4;<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas;color:black;background:white;mso-highlight:white"><o:p> </o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas;color:black;background:white;mso-highlight:white">// getting PPS config info<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas;color:black;background:white;mso-highlight:white">memcpy(acPPS, strTmp, 4);<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas;color:black;background:white;mso-highlight:white">memcpy(&acPPS[4], m_pcRtspStream->m_ustrPPS, m_pcRtspStream->m_iPPSLen);<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas;color:black;background:white;mso-highlight:white">nPPSLength = m_pcRtspStream->m_iPPSLen + 4;<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">// before passing data to be decoder add SPS, PPS and 4 byte of strTmp to the IDR NAL unit (<span style="font-size:9.5pt;font-family:Consolas;color:black;background:white;mso-highlight:white">pcbCompressedData</span>)<o:p></o:p></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas;color:black;background:white;mso-highlight:white">iStrTmpImageSize = nSPSLength + nPPSLength + 4 + nCompressedLength;<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas;color:black;background:white;mso-highlight:white">p = strTmpImage; // strTmpImage is empty allocated memory<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas;color:black;background:white;mso-highlight:white"><o:p> </o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas;color:black;background:white;mso-highlight:white">memcpy(p, acSPS, nSPSLength);<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas;color:black;background:white;mso-highlight:white">p += nSPSLength;<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas;color:black;background:white;mso-highlight:white"><o:p> </o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas;color:black;background:white;mso-highlight:white">memcpy(p, acPPS, nPPSLength);<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas;color:black;background:white;mso-highlight:white">p += nPPSLength;<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas;color:black;background:white;mso-highlight:white"><o:p> </o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas;color:black;background:white;mso-highlight:white">memcpy(p, strTmp, 4);<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas;color:black;background:white;mso-highlight:white">p += 4;<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas;color:black;background:white;mso-highlight:white"><o:p> </o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas;color:black;background:white;mso-highlight:white">memcpy(p, pcbCompressedData, nCompressedLength);<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas;color:black;background:white;mso-highlight:white">pHdr->nLength = iStrTmpImageSize;<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas;color:black;background:white;mso-highlight:white"><o:p> </o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.5pt;font-family:Consolas;color:black;background:white;mso-highlight:white">pcbCompressedData = strTmpImage;<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:9.5pt;font-family:Consolas;color:black;background:white;mso-highlight:white">nCompressedLength = iStrTmpImageSize;</span><span style="font-size:9.5pt;font-family:Consolas;color:black"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:9.5pt;font-family:Consolas;color:black"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:9.5pt;font-family:Consolas;color:black">// Pass
<span style="background:white;mso-highlight:white">pcbCompressedData</span> and <span style="background:white;mso-highlight:white">
nCompressedLength</span> to the decoder<o:p></o:p></span></p>
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