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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black">Dear ffmpeg experts,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black">How to list all supported resolutions of a webcam?<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black">Using the command line tool with the following command:<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black"><o:p> </o:p></span></p>
<p class="MsoNormal" style="text-indent:35.4pt"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black">ffmpeg -f dshow -list_options true -i video="HD Pro Webcam C920"<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black">I can successfully list all supported video resolutions and formats of the connected Logitech usb webcam. How can I get this list programmatically with
help of the C-API?<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black"><o:p> </o:p></span></p>
<pre style="background:white"><span lang="EN-US" style="font-family:"Arial",sans-serif;color:black">I can successfully open and stream this usb camera using the C-API, but I have to call<o:p></o:p></span></pre>
<pre style="background:white"><span lang="EN-US" style="font-family:Consolas;color:black">av_dict_set(&m_pInOptions, </span><span lang="EN-US" style="font-family:Consolas;color:#A31515">"video_size"</span><span lang="EN-US" style="font-family:Consolas;color:black">, sVideoSize.c_str(), 0);<o:p></o:p></span></pre>
<pre style="background:white"><span lang="EN-US" style="font-family:"Arial",sans-serif;color:black">with a supported video_size before calling</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">ret = avformat_open_inptut(&m_pFormatCtxInCam, </span><span lang="EN-US" style="font-family:Consolas;color:gray">szUrl</span><span lang="EN-US" style="font-family:Consolas;color:black">, m_pInFrmt, &m_pInOptions)<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"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black">by checking for
</span><span lang="EN-US" style="font-size:10.0pt;font-family:Consolas;color:black;mso-fareast-language:DE">ret == -5</span><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black"> I can retry opening the camera with a different
video_size.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black">At the moment I loop over a list with several standard video resolutions and try to open<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black">The webcam. This is very inconvienient. Also I would like return a list of supported resolutions.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black;mso-fareast-language:DE">Mit freundlichen Grüßen / Best regards<br>
<br>
</span><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#0070C0;mso-fareast-language:DE">Sven Hans</span><span style="font-size:12.0pt;font-family:"Times New Roman",serif;color:black;mso-fareast-language:DE"><br>
</span><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#0070C0;mso-fareast-language:DE">DERMALOG Identification Systems GmbH<br>
Systems Engineer</span><span style="font-size:12.0pt;font-family:"Times New Roman",serif;color:black;mso-fareast-language:DE"><br>
<br>
</span><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#7D7D7D;mso-fareast-language:DE">Mittelweg 120 | 20148 Hamburg | Germany</span><span style="font-size:12.0pt;font-family:"Times New Roman",serif;color:black;mso-fareast-language:DE"><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:DE">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:DE">Fax +49-40-413227-40<o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#7D7D7D;mso-fareast-language:DE">Mail
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<a href="https://www.dermalog.com"><span style="color:#7D7D7D">www.dermalog.com</span></a><o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US" style="font-size:12.0pt;font-family:"Times New Roman",serif;color:black;mso-fareast-language:DE"><br>
</span><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#0070C0;mso-fareast-language:DE">SECURITY – Made in Germany<br>
</span><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#7D7D7D;mso-fareast-language:DE">Biometrics * AFIS * ABIS * Face * Iris * Live Scanners * Border Control * ID Card & Passport Systems * National Identification Solutions
* Biometric Banking & Payment Solutions * Mobile Devices<br>
</span><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black;mso-fareast-language:DE"><br>
</span><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#0070C0;mso-fareast-language:DE">DERMALOG – The Biometrics Innovation Leader * Winner of 36 international Awards</span><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#548DD4;mso-fareast-language:DE"><br>
</span><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#7D7D7D;mso-fareast-language:DE">+ Innovator des Jahres 2018 - Innovator of the Year 2018 – brandeins Wissen Statista<br>
+ CEO 100 - Best 100 CEOs 2018 – Acquisition International<br>
+ CEO of the year 2018 Biometrics – CEO of the year 2018 – Acquisition International<br>
+ Deutschlands innovativste Mittelständler 2017 – Wirtschafts Woche<br>
-> Find out more about our international Awards </span><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#7D7D7D;mso-fareast-language:DE"><a href="https://www.dermalog.com/company/awards/"><span lang="EN-US" style="color:#7D7D7D">here</span></a></span><span lang="EN-US" style="font-size:12.0pt;font-family:"Times New Roman",serif;color:black;mso-fareast-language:DE"><br>
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</span><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#7D7D7D;mso-fareast-language:DE">This e-mail may contain information that is confidential or proprietary to DERMALOG Identification Systems GmbH. Any unauthorized disclosure,
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</span><span style="font-size:7.5pt;font-family:Webdings;color:#00B050;mso-fareast-language:DE">P</span><span lang="EN-US" style="font-size:7.5pt;font-family:"Arial",sans-serif;color:#00B050;mso-fareast-language:DE"> Please consider the environment before printing
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DERMALOG Identification Systems GmbH * Mittelweg 120, 20148 Hamburg, Germany<br>
CEO/Managing Director: Günther Mull * Commercial Register: AG Hamburg HRB 69547 <br>
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