<div dir="ltr">I think you want the "libx264" encoder. To use it, you need to install libx264, and your libav libraries need to have been built with the "enable-libx264" flag. It is enabled by default in most distributions, I think. The libx264 encoder has a lot of options; you should probably just pick one of its presets and use that. The accepted answer to this old post shows how you can do that using av_dict_set(): <a href="https://stackoverflow.com/questions/19146587/how-do-you-enable-veryfast-libx264-preset-from-code-using-libavcodec">https://stackoverflow.com/questions/19146587/how-do-you-enable-veryfast-libx264-preset-from-code-using-libavcodec</a><div><br></div><div>- Richard</div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Tue, Oct 8, 2019 at 1:58 PM Adhuran Adhuran <<a href="mailto:j.adhuran@surrey.ac.uk">j.adhuran@surrey.ac.uk</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
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Thank you very much.<br>
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Could you tell how I would be able to link x264 encoder for H264 and not v4l4m2m. To invoke x264 encoder with the source code.<br>
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Thanks in advance,<br>
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Kind Regards, <br>
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Adhuran <br>
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Sent from my Samsung Galaxy S9 - Powered by Three<br>
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Get <a href="https://aka.ms/ghei36" target="_blank">Outlook for Android</a></div>
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<div id="gmail-m_7116846005541760600divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>From:</b> Richard Hussong <<a href="mailto:rhussong@westpond.com" target="_blank">rhussong@westpond.com</a>><br>
<b>Sent:</b> Tuesday, October 8, 2019 6:46:26 PM<br>
<b>To:</b> This list is about using libavcodec, libavformat, libavutil, libavdevice and libavfilter. <<a href="mailto:libav-user@ffmpeg.org" target="_blank">libav-user@ffmpeg.org</a>><br>
<b>Cc:</b> Adhuran, Jayasingam (PG/R - Elec Electronic Eng) <<a href="mailto:j.adhuran@surrey.ac.uk" target="_blank">j.adhuran@surrey.ac.uk</a>><br>
<b>Subject:</b> Re: [Libav-user] Request for Help - Error - h264_v4l2m2m @ 0x114ac00] Could not find a valid device</font>
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<div dir="ltr">You need a V4L2 video device to use that encoder. If you haven't already done this, run "ls -l /dev/video*", and make sure there is a video device and you have permission to write to it. If that doesn't help, you should raise the logging level
of libav and see if it tells you what went wrong.
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<div>- Richard</div>
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<div dir="ltr" class="gmail_attr">On Tue, Oct 8, 2019 at 1:22 PM Adhuran Adhuran via Libav-user <<a href="mailto:libav-user@ffmpeg.org" target="_blank">libav-user@ffmpeg.org</a>> wrote:<br>
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Dear All,</div>
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I am trying to use ffmpeg source code top encode video streams in linux. I used the code provided in this link
<a href="https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fffmpeg.org%2Fdoxygen%2F3.2%2Fmuxing_8c_source.html&data=02%7C01%7Cj.adhuran%40surrey.ac.uk%7Cfeef03bf3fab4441db5208d74c17790f%7C6b902693107440aa9e21d89446a2ebb5%7C0%7C1%7C637061536017908633&sdata=DXwBLSqQMwhbyFnInOE%2F%2BYZ1TWzhIZhlNX2ZYKtG2rc%3D&reserved=0" id="gmail-m_7116846005541760600gmail-m_-3108037064996574237LPlnk871991" target="_blank">
https://ffmpeg.org/doxygen/3.2/muxing_8c_source.html</a> to encode videos.</div>
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I got an error, <span>when the code accessed the function ret = <a href="https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fffmpeg.org%2Fdoxygen%2F3.2%2Fgroup__lavc__core.html%23ga11f785a188d7d9df71621001465b0f1d&data=02%7C01%7Cj.adhuran%40surrey.ac.uk%7Cfeef03bf3fab4441db5208d74c17790f%7C6b902693107440aa9e21d89446a2ebb5%7C0%7C1%7C637061536017918630&sdata=hg0RqdJRa23310y5JSb8LXNAlfmbxtAKkSYSEh4iKVg%3D&reserved=0" target="_blank">
avcodec_open2</a>(c, codec, &opt);<br>
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<span>[h264_v4l2m2m @ 0x114ac00] Could not find a valid device<br>
</span>
<div>[h264_v4l2m2m @ 0x114ac00] can't configure encoder<br>
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May I know, why I get this error and how I could solve this?</div>
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Regards,</div>
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Adhuran.<br>
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