Hi,<div><br></div><div>I'm decoding video files using libavcodec etc. and I'm trying to scale the individual frames to a given size using sws_scale(). I'm working with 8-bit grayscale images only.</div><div>By writing out the frame buffers to files, and looking at them in an image editor, I've established that I am successfully reading and decoding the individual frames, but that the scaling is going wrong. </div>
<div>Approximately a third to a half of the frames scanlines are being correctly scaled, but then the scaler seems to throw a wobbly and return prematurely.</div><div>As you would probably expect, the return value corresponds to the number of scanlines that have been scaled, not the value that should have been scaled.</div>
<div><br></div><div>In short, the scaling looks like it is working perfectly, except for the fact that it's not processing all the scanlines ! </div><div>I'm reasonably sure I've got my scaling context and parameters set up correctly, because the partial scaled image result looks in proportion, the image corners look correct etc.</div>
<div><br></div><div><div>I've tried different pixel formats and frame dimensions but the result is essentially the same.</div></div><div><br></div><div>Any ideas please ? Could this be a bug ?</div><div><br></div><div>
My FFMPEG version is:</div><div><div>ffmpeg version N-33313-g1b3b4a5, Copyright (c) 2000-2011 the FFmpeg developers</div><div> built on Oct 6 2011 10:13:57 with gcc 4.4.3</div><div> configuration: </div><div> libavutil 51. 19. 0 / 51. 19. 0</div>
<div> libavcodec 53. 19. 0 / 53. 19. 0</div><div> libavformat 53. 14. 0 / 53. 14. 0</div><div> libavdevice 53. 4. 0 / 53. 4. 0</div><div> libavfilter 2. 43. 6 / 2. 43. 6</div><div> libswscale 2. 1. 0 / 2. 1. 0</div>
</div><div><br></div><div><br></div><div>Darren</div>