user11514: I have an interlaced video with MTS file format, which was captured using a HD camera.
When I play it using VLC, it is displayed at resolution 1920x1080 and if I take a snapshot with VLC, the saved image also has a resolution of 1920x1080. I tried playing the video with the Windows Media Player, and the video is also rendered at a resolution of 1920x1080.
However, in VLC, when I select Tools > Codecs information I get the following :
Type: Video
Id original: 4113
Codec: H264 - MPEG-4 AVC (part10) (h264)
Resolution: 1440x1080
Framerate: 25
Decoded format: Planar 4:2:0 YUV

(there also are an audio stream and a subtitle stream, which I am not interested in).
So the exposed resolution seems to be 1440x1080 but when rendered the video is 1920x1080.
Anyway, my true problem comes from the fact that I need to extract the frames from the video to perform some Image Processing. I do that using ffmpeg, which extracts frames at the resolution of 1440x1080, but then the extracted images seem distorted (i.e. compressed horizontally), which causes errors for the Image Processing I am doing.
Any idea why VLC, Windows Media Player, Power DVD manages to render the video correctly, whereas ffmpeg fails to extract the frames at the correct resolution ? And why is the video rendered at 1920x1080 if the exposed codec resolution is 1440x1080 ?

user3908: HDV camera, right? It's not untypical for cameras to claim higher resolution than they actually scan. In such cases you have to look at the different aspect ratios involved: pixel, frame, display, sample. Here's a post that discusses this, or google "HDV aspect ratio". And here's a link to the spec from the HDV consortium.
It's essentially anamorphic. The ffmpeg or avconv docs should show how to extract and expand to 1920 in one step.

11514: <p>I have an interlaced video with MTS file format, which was captured using a HD camera.
When I play it using VLC, it is displayed at resolution 1920x1080 and if I take a snapshot with VLC, the saved image also has a resolution of 1920x1080. I tried playing the video with the Windows Media Player, and the video is also rendered at a resolution of 1920x1080.</p>

<p>However, in VLC, when I select <strong>Tools > Codecs information</strong> I get the following :</p>

<pre><code>Type: Video
Id original: 4113
Codec: H264 - MPEG-4 AVC (part10) (h264)
Resolution: 1440x1080
Framerate: 25
Decoded format: Planar 4:2:0 YUV
</code></pre>

<p>(there also are an audio stream and a subtitle stream, which I am not interested in).</p>

<p>So the exposed resolution seems to be 1440x1080 but when rendered the video is 1920x1080.</p>

<p>Anyway, <strong>my true problem</strong> comes from the fact that I need to extract the frames from the video to perform some Image Processing. I do that using <code>ffmpeg</code>, which extracts frames at the resolution of 1440x1080, but then the extracted images seem distorted (i.e. compressed horizontally), which causes errors for the Image Processing I am doing.</p>

<p>Any idea why VLC, Windows Media Player, Power DVD manages to render the video correctly, whereas <code>ffmpeg</code> fails to extract the frames at the correct resolution ? And why is the video rendered at 1920x1080 if the exposed codec resolution is 1440x1080 ?</p>
 3908: <p>HDV camera, right? It's not untypical for cameras to claim higher resolution than they actually scan. In such cases you have to look at the different aspect ratios involved: pixel, frame, display, sample. <a href="http://forum.videohelp.com/threads/323530-please-explain-SAR-DAR-PAR" rel="nofollow"><strong>Here's a post</strong></a> that discusses this, or google "HDV aspect ratio". And <a href="https://documentation.apple.com/en/finalcutpro/professionalformatsandworkflows/chapter_2_section_6.html" rel="nofollow"><strong>here's a link</strong></a> to the spec from the HDV consortium.</p>

<p>It's essentially anamorphic. The ffmpeg or avconv docs should show how to extract and expand to 1920 in one step.</p>
