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<pre style="background:white"><span lang="EN-US">Hi, <o:p></o:p></span></pre>
<pre style="background:white"><span lang="EN-US">thank you for your support. Maybe you can help me a bit more:<o:p></o:p></span></pre>
<pre style="background:white"><span lang="EN-US"><o:p> </o:p></span></pre>
<pre style="background:white"><span lang="EN-US">I just tried the API, but without success.<o:p></o:p></span></pre>
<pre style="background:white"><span lang="EN-US">The error is -40 (“function not implemented”) from <o:p></o:p></span></pre>
<pre style="background:white"><span lang="EN-US">the function <b>avdevice_capabilities_create. </b>I use the libs/dlls released with ffmpeg 4.1.0 on Windows 10. My project is build with Visual Studio vc14_xp.<o:p></o:p></span></pre>
<pre style="background:white"><span lang="EN-US">Maybe I did not initialize everything correctly or bad ordering of open input?<o:p></o:p></span></pre>
<pre style="background:white"><span lang="EN-US">Please see my code:<o:p></o:p></span></pre>
<pre style="background:white"><span lang="EN-US" style="font-family:Consolas;color:blue"><o:p> </o:p></span></pre>
<pre style="background:white"><span lang="EN-US" style="font-family:Consolas;color:blue">const</span><span lang="EN-US" style="font-family:Consolas;color:black"> </span><span lang="EN-US" style="font-family:Consolas;color:blue">char</span><span lang="EN-US" style="font-family:Consolas;color:black">* szUrl</span><span lang="EN-US" style="font-family:Consolas;color:gray"> = </span><span lang="EN-US" style="font-family:Consolas;color:#A31515">"video=@device_pnp_\\?\usb#vid_046d&pid_082d&mi_00#7&1d276e35&0&0000#{65e8773d-8f56-11d0-a3b9-00a0c9223196}\global"</span><span lang="EN-US" style="font-family:Consolas;color:black"><o:p></o:p></span></pre>
<p class="MsoNormal" style="background:white"><span lang="EN-US" style="font-size:10.0pt;font-family:Consolas;color:black"><o:p> </o:p></span></p>
<pre style="background:white"><span lang="EN-US" style="font-family:Consolas;color:green">// register all codecs and devices</span><span lang="EN-US" style="font-family:Consolas;color:black"><o:p></o:p></span></pre>
<pre style="background:white"><span lang="EN-US" style="font-family:Consolas;color:black">av_register_all();<o:p></o:p></span></pre>
<pre style="background:white"><span lang="EN-US" style="font-family:Consolas;color:black">avcodec_register_all();<o:p></o:p></span></pre>
<pre style="background:white"><span lang="EN-US" style="font-family:Consolas;color:black">avdevice_register_all();<o:p></o:p></span></pre>
<pre style="background:white"><span lang="EN-US" style="font-family:Consolas;color:black">av_log_set_level(</span><span lang="EN-US" style="font-family:Consolas;color:#6F008A">AV_LOG_ERROR</span><span lang="EN-US" style="font-family:Consolas;color:black">); </span><span lang="EN-US" style="font-family:Consolas;color:green">//turn off info and warning; only output error</span><span lang="EN-US" style="font-family:Consolas;color:black"><o:p></o:p></span></pre>
<pre style="background:white"><span lang="EN-US" style="font-family:Consolas;color:#2B91AF">AVFormatContext</span><span lang="EN-US" style="font-family:Consolas;color:black">* m_pFormatCtxInCam = avformat_alloc_context();<o:p></o:p></span></pre>
<pre style="background:white"><span lang="EN-US" style="font-family:Consolas;color:#2B91AF">AVInputFormat</span><span lang="EN-US" style="font-family:Consolas;color:black">* m_pInFrmt = av_find_input_format(</span><span lang="EN-US" style="font-family:Consolas;color:#A31515">"dshow"</span><span lang="EN-US" style="font-family:Consolas;color:black">);<o:p></o:p></span></pre>
<pre style="background:white"><span lang="EN-US" style="font-family:Consolas;color:black"><o:p> </o:p></span></pre>
<p class="MsoNormal" style="background:white"><span lang="EN-US" style="font-size:10.0pt;font-family:Consolas;color:#2B91AF">AVDictionary</span><span lang="EN-US" style="font-size:10.0pt;font-family:Consolas;color:black"> *m_pInOptions =
</span><span lang="EN-US" style="font-size:10.0pt;font-family:Consolas;color:blue">nullptr</span><span lang="EN-US" style="font-size:10.0pt;font-family:Consolas;color:black">;</span><span lang="EN-US" style="font-size:10.0pt;font-family:Consolas;color:black"><o:p></o:p></span></p>
<p class="MsoNormal" style="background:white"><span lang="EN-US" style="font-size:10.0pt;font-family:Consolas;color:black">av_dict_set(&m_pInOptions, </span><span lang="EN-US" style="font-size:10.0pt;font-family:Consolas;color:#A31515">"video_size"</span><span lang="EN-US" style="font-size:10.0pt;font-family:Consolas;color:black">, </span><span lang="EN-US" style="font-size:10.0pt;font-family:Consolas;color:#A31515">"640x480"</span><span lang="EN-US" style="font-size:10.0pt;font-family:Consolas;color:black">, 0);<o:p></o:p></span></p>
<p class="MsoNormal" style="background:white"><span lang="EN-US" style="font-size:10.0pt;font-family:Consolas;color:black">av_dict_set(&m_pInOptions, </span><span lang="EN-US" style="font-size:10.0pt;font-family:Consolas;color:#A31515">"framerate"</span><span lang="EN-US" style="font-size:10.0pt;font-family:Consolas;color:black">,</span><span lang="EN-US" style="font-size:10.0pt;font-family:Consolas;color:#A31515">
"30"</span><span lang="EN-US" style="font-size:10.0pt;font-family:Consolas;color:black">, 0);<o:p></o:p></span></p>
<pre style="background:white"><span lang="EN-US" style="font-family:Consolas;color:blue">int</span><span lang="EN-US" style="font-family:Consolas;color:black"> ret = avformat_open_input(&m_pFormatCtxInCam, szUrl, m_pInFrmt, &m_pInOptions)<o:p></o:p></span></pre>
<p class="MsoNormal" style="background:white"><span lang="EN-US" style="font-size:10.0pt;font-family:Consolas;color:black">if(ret >= 0)<o:p></o:p></span></p>
<p class="MsoNormal" style="background:white"><span lang="EN-US" style="font-size:10.0pt;font-family:Consolas;color:black">{<o:p></o:p></span></p>
<pre style="background:white"><span lang="EN-US" style="font-family:Consolas;color:#2B91AF"> AVDeviceCapabilitiesQuery</span><span lang="EN-US" style="font-family:Consolas;color:black"> * pDevCap = </span><span lang="EN-US" style="font-family:Consolas;color:blue">nullptr</span><span lang="EN-US" style="font-family:Consolas;color:black">;<o:p></o:p></span></pre>
<pre style="background:white"><span lang="EN-US" style="font-family:Consolas;color:#2B91AF"> AVOptionRanges</span><span lang="EN-US" style="font-family:Consolas;color:black"> * pPixFmtRange;<o:p></o:p></span></pre>
<pre style="background:white"><span lang="EN-US" style="font-family:Consolas;color:black"> ret = avdevice_capabilities_create(&pDevCap, m_pFormatCtxInCam, </span><span lang="EN-US" style="font-family:Consolas;color:blue">nullptr</span><span lang="EN-US" style="font-family:Consolas;color:black">);<o:p></o:p></span></pre>
<pre style="background:white"><span lang="EN-US" style="font-family:Consolas;color:blue"> if</span><span lang="EN-US" style="font-family:Consolas;color:black">(ret >= 0)<o:p></o:p></span></pre>
<pre style="background:white"><span lang="EN-US" style="font-family:Consolas;color:black"> {<o:p></o:p></span></pre>
<pre style="background:white"><span lang="EN-US" style="font-family:Consolas;color:blue"> if</span><span lang="EN-US" style="font-family:Consolas;color:black">(av_opt_query_ranges(&pPixFmtRange, pDevCap, </span><span lang="EN-US" style="font-family:Consolas;color:#A31515">"pixel_format"</span><span lang="EN-US" style="font-family:Consolas;color:black">, <o:p></o:p></span></pre>
<pre style="background:white"><span lang="EN-US" style="font-family:Consolas;color:black"> </span><span lang="EN-US" style="font-family:Consolas;color:#6F008A">AV_OPT_MULTI_COMPONENT_RANGE</span><span lang="EN-US" style="font-family:Consolas;color:black">) >= 0)<o:p></o:p></span></pre>
<pre style="background:white"><span lang="EN-US" style="font-family:Consolas;color:black"> {<o:p></o:p></span></pre>
<pre style="background:white"><span lang="EN-US" style="font-family:Consolas;color:black"> std::cout </span><span lang="EN-US" style="font-family:Consolas;color:teal"><<</span><span lang="EN-US" style="font-family:Consolas;color:black"> </span><span lang="EN-US" style="font-family:Consolas;color:#A31515">"found some pixel formats"</span><span lang="EN-US" style="font-family:Consolas;color:black"> </span><span lang="EN-US" style="font-family:Consolas;color:teal"><<</span><span lang="EN-US" style="font-family:Consolas;color:black"> std::endl; <o:p></o:p></span></pre>
<pre style="background:white"><span lang="EN-US" style="font-family:Consolas;color:black"> }<o:p></o:p></span></pre>
<pre style="background:white"><span lang="EN-US" style="font-family:Consolas;color:black"> av_opt_freep_ranges(&pPixFmtRange);<o:p></o:p></span></pre>
<pre style="background:white"><span lang="EN-US" style="font-family:Consolas;color:black"> }<o:p></o:p></span></pre>
<pre style="background:white"><span lang="EN-US" style="font-family:Consolas;color:blue"> else</span><span lang="EN-US" style="font-family:Consolas;color:black"><o:p></o:p></span></pre>
<pre style="background:white"><span lang="EN-US" style="font-family:Consolas;color:black"> {<o:p></o:p></span></pre>
<pre style="background:white"><span lang="EN-US" style="font-family:Consolas;color:black"> </span><span lang="EN-US" style="font-family:Consolas;color:blue">char</span><span lang="EN-US" style="font-family:Consolas;color:black"> szErrbuf[1024];<o:p></o:p></span></pre>
<pre style="background:white"><span lang="EN-US" style="font-family:Consolas;color:black"> av_strerror(ret, szErrbuf, 1024); <o:p></o:p></span></pre>
<pre style="background:white"><span lang="EN-US" style="font-family:Consolas;color:black"> }<o:p></o:p></span></pre>
<pre style="background:white"><span lang="EN-US" style="font-family:Consolas;color:black"> avdevice_capabilities_free(&pDevCap, m_pFormatCtxInCam);<o:p></o:p></span></pre>
<pre style="background:white"><span style="font-family:"Arial",sans-serif;color:black;mso-fareast-language:EN-US">}</span><span style="font-family:Consolas;color:black"><o:p></o:p></span></pre>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black">Mit freundlichen Grüßen / Best regards<br>
<br>
</span><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#0070C0">Sven Hans</span><span style="color:black"><br>
</span><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#0070C0">DERMALOG Identification Systems GmbH<br>
Systems Engineer</span><span style="color:black"><br>
<br>
</span><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#7D7D7D">Mittelweg 120 | 20148 Hamburg</span><span style="color:black"><o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#7D7D7D;mso-fareast-language:EN-US">Fon +49 40 413227 0<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#7D7D7D;mso-fareast-language:EN-US">Fax +49-40-413227-40<o:p></o:p></span></p>
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</span><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#7D7D7D">This e-mail may contain information that is confidential or proprietary to DERMALOG Identification Systems GmbH. Any unauthorized disclosure, distribution or other
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</span><span style="font-size:7.5pt;font-family:Webdings;color:#00B050">P</span><span lang="EN-US" style="font-size:7.5pt;font-family:"Arial",sans-serif;color:#00B050"> Please consider the environment before printing this email</span><span lang="EN-US" style="font-family:"Arial",sans-serif;color:black">
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<p class="MsoNormal"><b><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif">From:</span></b><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif"> Libav-user <libav-user-bounces@ffmpeg.org>
<b>On Behalf Of </b>Hristo Ivanov<br>
<b>Sent:</b> Mittwoch, 17. April 2019 11:44<br>
<b>To:</b> This list is about using libavcodec, libavformat, libavutil, libavdevice and libavfilter. <libav-user@ffmpeg.org><br>
<b>Subject:</b> Re: [Libav-user] list all available formats of webcam<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US" style="font-family:"Courier New"">Hi.</span><span lang="EN-US"><o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US" style="font-family:"Courier New"">Sorry, I think I got it wrong in my previous reply:</span><span lang="EN-US"><o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US" style="font-family:"Courier New"">> I think there is no way to retrieve the information using the FFMPEG API.</span><span lang="EN-US"><o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US" style="font-family:"Courier New"">There is this:</span><span lang="EN-US"><o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
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<p class="MsoNormal"><a href="https://ffmpeg.org/doxygen/trunk/structAVDeviceCapabilitiesQuery.html"><span lang="EN-US" style="font-family:"Courier New"">https://ffmpeg.org/doxygen/trunk/structAVDeviceCapabilitiesQuery.html</span></a><span lang="EN-US" style="font-family:"Courier New""> </span><span lang="EN-US"><o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US" style="font-family:"Courier New""> </span><span lang="EN-US"><o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US" style="font-family:"Courier New"">Quoting the docs:</span><span lang="EN-US"><o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US" style="font-family:"Courier New"">> <span style="color:black">Following API allows user to probe device capabilities (supported codecs, pixel formats, sample formats, resolutions, channel counts, etc).</span></span><span lang="EN-US"><o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US" style="font-family:"Courier New"">Give the above API a try.</span><span lang="EN-US"><o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US" style="font-family:"Courier New"">> <span style="color:black">So the output in the console comes from the backend and not from ffmpeg?</span></span><span lang="EN-US"><o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US" style="font-family:"Courier New";color:black">Well, the output comes from ffmpeg, it gets printed with the av_log() function.</span><span lang="EN-US"><o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US" style="font-family:"Courier New";color:black">For the decklink '-listformats' flag, the output just gets printed and it is not stored in any structure(not even in the above API) from which it can be retrieved.</span><span lang="EN-US"><o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US" style="font-family:"Courier New";color:black">That is why I had to capture the log and then parse it.</span><span lang="EN-US"><o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Courier New";color:black">> probably I have to implement this functionality directly with Dshow in Windows and v4l2 in Linux.</span><span lang="EN-US"><o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Courier New";color:black">Doing this with the decklink API for my case would be a better solution than the one I currently have.</span><span lang="EN-US"><o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Courier New"">Regards.</span><o:p></o:p></p>
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