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  1. Member
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    I have an issue which I hope people here can help with. I use a DVD recorder to record programs from DirecTV. I make a DVD of the show and copy it onto my computer using makeMKV. The original DVD has an AR of 16:9. For some reason the resulting MKV file has an AR of 4:3. Playing this file it is clearly 4:3 when using VLC mediaplayer on my computer. Using MKVToolNix, I can change the AR of the file back to 16:9. If I play this file, it is recognized as 16:9 by VLC.

    Then using either BDRebuilder or MultiAVCHD to create a BD architecture for these MKV files, the m2ts files which have been created have somehow reverted back to an AR of 4:3.

    If I "recode" the files using BDRebilder the resulting files are back to 16:9!

    I don't know why this is happening. I would like to find a program that can change the AR of m2ts files back to 16:9 so I can burn them to a BD.

    Thanks.

    SMK
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    Originally Posted by RoyGBiv-inRI View Post
    I have an issue which I hope people here can help with. I use a DVD recorder to record programs from DirecTV. I make a DVD of the show and copy it onto my computer using makeMKV. The original DVD has an AR of 16:9. For some reason the resulting MKV file has an AR of 4:3. Playing this file it is clearly 4:3 when using VLC mediaplayer on my computer. Using MKVToolNix, I can change the AR of the file back to 16:9. If I play this file, it is recognized as 16:9 by VLC.

    Then using either BDRebuilder or MultiAVCHD to create a BD architecture for these MKV files, the m2ts files which have been created have somehow reverted back to an AR of 4:3.

    If I "recode" the files using BDRebilder the resulting files are back to 16:9!

    I don't know why this is happening. I would like to find a program that can change the AR of m2ts files back to 16:9 so I can burn them to a BD.

    Thanks.

    SMK
    First, it is doubtful that your original DVD contains video with its aspect ratio flag set to 16:9. The only source for which US DVD recorders may be able to correctly set an aspect ratio in the recorded video automatically is the digital tuner, and this is possible because there is an aspect ratio flag embedded in the broadcast signal. ...but the DVD recorder's digital tuner cannot be used to record from DirecTV.

    Because there is no aspect ratio information transmitted in NTSC channels, composite video signals, or S-video signals, US model DVD recorders record them with the video's aspect ratio flag set to 4:3 by default.

    So, unless you can manually specify an aspect ratio using one of your DVD recorder's optional settings, the video will be recorded with 4:3 aspect ratio flag. ...and if there is a setting controlling the aspect ratio, it may only affect the aspect ratio flags in the IFOs, not the aspect ratio flag in the video itself.

    MKVToolnix may only set the AR flag in the MKV headers, not in the video's own headers.

    Now, how to fix the problem? When I use a DVD recorder to record from a 16:9 channel using an analog connection from a set top box, I use the free version of VOB2MPG to create mpg files from the DVD, then use DVDPatcher to change the aspect ratio on the entire file, not just the first header. With the video itself flagged as 16:9, it should still be 16:9 after converting to an mts file, even if you do not re-encode it.
    Last edited by usually_quiet; 10th Dec 2017 at 12:32.
    Ignore list: hello_hello, tried, TechLord, Snoopy329
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  3. The issue may be an MPEG sequence_display_extension. The MPEG video is marked 4:3 DAR but a sequence_display_extension indicates that DAR is contained in a 540x480 portion of the frame. That makes the full 720x480 frame 16:9 DAR. Most programs don't understand that and treat the full frame as 4:3. Remuxing to MKV with a 16:9 flag works for media players playing the MKV file. But the MPEG DAR and sequence_display_extension are still in the MPEG data. Demuxing out of the MKV container removes the MKV header DAR and you're back to the MPEG settings.

    GSpot can show you if a sequence_display_extension appears in the video (see the "seq ext" field). You can use DVDPatcher to change MPEG DAR to 16:9 but the sequence_display_extension will remain. Any program which understands it will play the video super wide, ~2.37:1.
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    Originally Posted by jagabo View Post
    The issue may be an MPEG sequence_display_extension. The MPEG video is marked 4:3 DAR but a sequence_display_extension indicates that DAR is contained in a 540x480 portion of the frame. That makes the full 720x480 frame 16:9 DAR. Most programs don't understand that and treat the full frame as 4:3. Remuxing to MKV with a 16:9 flag works for media players playing the MKV file. But the MPEG DAR and sequence_display_extension are still in the MPEG data. Demuxing out of the MKV container removes the MKV header DAR and you're back to the MPEG settings.

    GSpot can show you if a sequence_display_extension appears in the video (see the "seq ext" field). You can use DVDPatcher to change MPEG DAR to 16:9 but the sequence_display_extension will remain. Any program which understands it will play the video super wide, ~2.37:1.
    Have you ever seen this scenario when the DVD in question originates from a DVD recorder?
    Ignore list: hello_hello, tried, TechLord, Snoopy329
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  5. Originally Posted by usually_quiet View Post
    Originally Posted by jagabo View Post
    The issue may be an MPEG sequence_display_extension. The MPEG video is marked 4:3 DAR but a sequence_display_extension indicates that DAR is contained in a 540x480 portion of the frame. That makes the full 720x480 frame 16:9 DAR. Most programs don't understand that and treat the full frame as 4:3. Remuxing to MKV with a 16:9 flag works for media players playing the MKV file. But the MPEG DAR and sequence_display_extension are still in the MPEG data. Demuxing out of the MKV container removes the MKV header DAR and you're back to the MPEG settings.

    GSpot can show you if a sequence_display_extension appears in the video (see the "seq ext" field). You can use DVDPatcher to change MPEG DAR to 16:9 but the sequence_display_extension will remain. Any program which understands it will play the video super wide, ~2.37:1.
    Have you ever seen this scenario when the DVD in question originates from a DVD recorder?
    Yes. The last one was just a few weeks ago, recorded in Japan.
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  6. restream can be used to strip or overwrite the sequence display extension
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  7. Originally Posted by poisondeathray View Post
    restream can be used to strip or overwrite the sequence display extension
    I just checked -- and it worked. I set the DAR to 16:9 and removed the sequence_display_extension.
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  8. Member
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    Originally Posted by jagabo View Post
    Originally Posted by usually_quiet View Post
    Originally Posted by jagabo View Post
    The issue may be an MPEG sequence_display_extension. The MPEG video is marked 4:3 DAR but a sequence_display_extension indicates that DAR is contained in a 540x480 portion of the frame. That makes the full 720x480 frame 16:9 DAR. Most programs don't understand that and treat the full frame as 4:3. Remuxing to MKV with a 16:9 flag works for media players playing the MKV file. But the MPEG DAR and sequence_display_extension are still in the MPEG data. Demuxing out of the MKV container removes the MKV header DAR and you're back to the MPEG settings.

    GSpot can show you if a sequence_display_extension appears in the video (see the "seq ext" field). You can use DVDPatcher to change MPEG DAR to 16:9 but the sequence_display_extension will remain. Any program which understands it will play the video super wide, ~2.37:1.
    Have you ever seen this scenario when the DVD in question originates from a DVD recorder?
    Yes. The last one was just a few weeks ago, recorded in Japan.
    It turns out that I have many, many files with similar characteristics, but I didn't know it because MediaInfo says that they are 16:9 AR, as does AVStoDVD. All of them were recorded using my present DVD recorder's digital tuner as the source.

    When I used the same DVD recorder's S-video or composite video connection as the source, GSpot reports a 4:3 DAR with a sequence extension of 720x480. MediaInfo agrees that they are 4:3 AR. Before I discovered DVDPatcher, I used to demultiplex these kinds of files and use Restream to correct the elementary video file's AR. Back then the DVD recoder I had produced video with a 704x480 resolution where GSpot reports a 4:3 DAR with a sequence extension of 720x480!
    Last edited by usually_quiet; 10th Dec 2017 at 14:24. Reason: spelling
    Ignore list: hello_hello, tried, TechLord, Snoopy329
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    Thanks for all of the information. I will try VOB2MPG and DVDPatcher.

    SMK
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    I finally got around to using DVDPatcher. It turns out it accepts both MKV and M2TS files, and I was able to do exactly what I wanted using just it to change the entire file's AR. Thanks for pointing me in the right direction.

    SMK
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