<div dir="ltr">If you convert any RGB format to YUV420 you will lose data. If you want to just change the format to YCbCr without losing data.. you can try YUV444 format... its 3 bytes per pixel, just like RGB, so you will not lose any data.</div><div class="gmail_extra"><br><div class="gmail_quote">2015-05-27 9:25 GMT-03:00 Jasleen Kaur <span dir="ltr"><<a href="mailto:Jasleen@beesys.com" target="_blank">Jasleen@beesys.com</a>></span>:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
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<div>We have ARGB buffer to be compressed and then decoded also.</div>
<div>But for encoding the data the input as ARGB wasnt accepted.</div>
<div>The data was converted to YUV and then compressed, and on the receive side decoded and then converted back to ARGB.</div>
<div><br>
</div>
<div><b>The problem is that, While this conversion happens colours change.</b></div>
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</div>
<div>Following is the code used to convert from ARGB to YUV and YUV to ARGB respectively.</div>
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</div>
<div><br>
</div>
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<div>void <b>ConvertToYUV</b>(int iWidth, int iHeight, BYTE* pARGBBuff)</div>
<div>{<span style="white-space:pre-wrap"> </span></div>
<div><span style="white-space:pre-wrap"></span>#define RNDTO2(X) ( ( (X) & 0xFFFFFFFE )</div>
<div><span style="white-space:pre-wrap"></span>#define RNDTO32(X) ( ( (X) % 32 ) ? ( ( (X) + 32 ) & 0xFFFFFFE0 ) : (X) )</div>
<div><br>
</div>
<div><span style="white-space:pre-wrap"></span>//int ystride = RNDTO32 ( iWidth );</div>
<div> //int uvstride = RNDTO32 ( iWidth / 2 );</div>
<div><span style="white-space:pre-wrap"></span>int ystride = iWidth;</div>
<div> int uvstride = iWidth / 2;</div>
<div> int ysize = ystride * iHeight;</div>
<div> int vusize = uvstride * ( iHeight / 2 );</div>
<div> int size = ysize + ( 2 * vusize );</div>
<div><br>
</div>
<div><span style="white-space:pre-wrap"></span>if(m_sws_ctx == NULL)</div>
<div><span style="white-space:pre-wrap"></span>{</div>
<div><span style="white-space:pre-wrap"></span>//SwsFilter</div>
<div><span style="white-space:pre-wrap"></span>m_sws_ctx = sws_getContext(iWidth, </div>
<div><span style="white-space:pre-wrap"></span>iHeight,</div>
<div><span style="white-space:pre-wrap"></span>AV_PIX_FMT_BGRA, </div>
<div><span style="white-space:pre-wrap"></span>iWidth, iHeight,</div>
<div><span style="white-space:pre-wrap"></span>AV_PIX_FMT_YUV420P, </div>
<div><span style="white-space:pre-wrap"></span>SWS_FAST_BILINEAR, 0, 0, 0);</div>
<div><br>
</div>
<div><span style="white-space:pre-wrap"></span>m_picture_buf = (uint8_t*)malloc(size);</div>
<div><span style="white-space:pre-wrap"></span>}<span style="white-space:pre-wrap">
</span></div>
<div><span style="white-space:pre-wrap"></span></div>
<div> //uint8_t *plane[] = { m_picture_buf, m_picture_buf + ysize, m_picture_buf + ysize + vusize};</div>
<div><span style="white-space:pre-wrap"></span>uint8_t *plane[] = { m_picture_buf, m_picture_buf + ysize + vusize, m_picture_buf + ysize};</div>
<div> int stride[] = { ystride, uvstride, uvstride};</div>
<div><br>
</div>
<div><span style="white-space:pre-wrap"></span>uint8_t *inData[1] = { pARGBBuff };</div>
<div> int inLinesize[1] = { 4 * iWidth}; </div>
<div><br>
</div>
<div> sws_scale(m_sws_ctx, inData, inLinesize, 0, iHeight, plane, stride);<span style="white-space:pre-wrap">
</span></div>
<div><span style="white-space:pre-wrap"></span></div>
<div>}</div>
</div>
<br>
<div>
<div>
<div>void <b>ConvertToARGB</b>(int iWidth, int iHeight)</div>
<div>{<span style="white-space:pre-wrap"> </span></div>
<div><span style="white-space:pre-wrap"></span>#define RNDTO2(X) ( ( (X) & 0xFFFFFFFE )</div>
<div><span style="white-space:pre-wrap"></span>#define RNDTO32(X) ( ( (X) % 32 ) ? ( ( (X) + 32 ) & 0xFFFFFFE0 ) : (X) )</div>
<div><br>
</div>
<div><span style="white-space:pre-wrap"></span>int iSize = iWidth * iHeight * 4;</div>
<div><span style="white-space:pre-wrap"></span>int ystride = RNDTO32 ( iWidth );</div>
<div> int uvstride = RNDTO32 ( iWidth / 2 );<span style="white-space:pre-wrap">
</span></div>
<div> int ysize = ystride * iHeight;</div>
<div> int vusize = uvstride * ( iHeight / 2 );</div>
<div> </div>
<div><br>
</div>
<div><span style="white-space:pre-wrap"></span>if(m_sws_ctx == NULL)</div>
<div><span style="white-space:pre-wrap"></span>{</div>
<div><span style="white-space:pre-wrap"></span>//SwsFilter</div>
<div><span style="white-space:pre-wrap"></span>m_sws_ctx = sws_getContext(iWidth, </div>
<div><span style="white-space:pre-wrap"></span>iHeight,</div>
<div><span style="white-space:pre-wrap"></span>AV_PIX_FMT_YUV420P, </div>
<div><span style="white-space:pre-wrap"></span>iWidth, iHeight,</div>
<div><span style="white-space:pre-wrap"></span>AV_PIX_FMT_BGRA, </div>
<div><span style="white-space:pre-wrap"></span>SWS_FAST_BILINEAR, 0, 0, 0);</div>
<div><br>
</div>
<div><span style="white-space:pre-wrap"></span>m_picture_buf = (uint8_t*)malloc(iSize);</div>
<div><span style="white-space:pre-wrap"></span>}<span style="white-space:pre-wrap">
</span></div>
<div><span style="white-space:pre-wrap"></span></div>
<div><span style="white-space:pre-wrap"></span>// src<span style="white-space:pre-wrap">
</span></div>
<div><span style="white-space:pre-wrap"></span>int srcstride[] = {ystride, uvstride, uvstride}; </div>
<div><br>
</div>
<div><span style="white-space:pre-wrap"></span>// dest</div>
<div><span style="white-space:pre-wrap"></span>uint8_t *destplane[] = {m_picture_buf};</div>
<div> int stride[] = { iWidth * 4};<span style="white-space:pre-wrap">
</span></div>
<div><span style="white-space:pre-wrap"></span></div>
<div> int iHeightReturned = sws_scale(m_sws_ctx, m_picture->data, srcstride, 0, iHeight, destplane, stride);<span style="white-space:pre-wrap">
</span><span style="font-size:10pt;white-space:pre-wrap"></span></div>
<div> </div>
<div><b> <span style="font-size:13.3333330154419px">m_picture is the output of </span><span style="font-size:10pt">avcodec_decode_video2.</span></b><span style="font-size:10pt;white-space:pre-wrap">
</span></div>
<div>}</div>
<div><br>
</div>
<div><br>
</div>
<div>What correction needs to be done in the code, so that colours remain intact.</div>
<div><br>
</div>
<div>Thanks and regards</div><span class="HOEnZb"><font color="#888888">
<div>Jasleen</div>
</font></span></div>
</div>
</div>
</div>
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