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  1. I am converting from DV to MPEG-2 at 480x480 resolution. Since I am storing files on hard disk I am trying for the smallest file size with no visable quality loss. I thought everything was fine until I did my first full length movie. In sceens where there is mild motion the picture slightly skips once in a while as if frames are dropped. There were no dropped frames during capture.

    I am using CQ at a bitrate of 2600 and a quality of 65. I wonder if the bitrate is too low.

    I also wonder about the GOP structure. I am using 1,5,2 with a max of 18 frames per GOP so it looks like IBBPBBPBBPBBPBBPBB I (open).

    Any suggestions? My first thought is to increase the bitrate to 2800-3000.

    Thanks
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  2. I am still trying to get the parameters just right. I re-encoded at a max bitrate of 3000. I appears to have either reduced or eliminated the drop frame effect. Ther are now areas where I am not sure if I am seeing dropped frames. they may be less or it may be my imagination.

    The file size is still quite small. For about a 1 1/2 hour movie:

    2600: 817 MB
    3000: 825 MB

    Still hoping for some help.

    Thanks
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  3. Originally Posted by neo
    I am still trying to get the parameters just right. I re-encoded at a max bitrate of 3000. I appears to have either reduced or eliminated the drop frame effect. Ther are now areas where I am not sure if I am seeing dropped frames. they may be less or it may be my imagination.

    The file size is still quite small. For about a 1 1/2 hour movie:

    2600: 817 MB
    3000: 825 MB

    Still hoping for some help.

    Thanks
    Well I read somewhere where the minimum bitrate should not be lower than 1200 and the maximum should not be greater than 2700 so I used these. Unfortunately, this increased the file size to 1200 MB or about a 50% increase.
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  4. Member
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    I assume you are making SVCDs . An hour is pushing it.
    I would suggest a 2 pass VBR encode at 2600 with
    TMPGenc .
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  5. Originally Posted by FOO
    I assume you are making SVCDs . An hour is pushing it.
    I would suggest a 2 pass VBR encode at 2600 with
    TMPGenc .
    Thanks for the help. As I said at the beginning I am storing on hard drive for playback on my monitor. I tried 2 pass VBR at 2600 and the quality was worse. When I checked the 2 pass log there were not enough samples and the BR did not vary as much as CQ. I think the BR varies too much from each GOP to the next. By having the Min BR at 0 it can really reduce the file size by dropping the BR very low when not needed.

    I do not know why someone said the minimum should be 1200 but this makes a huges difference in file size. It just seems to increase the BR where it is not needed.

    I may try an even higher BR at CQ.

    Thanks
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  6. Member
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    never mind
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  7. Originally Posted by neo
    I do not know why someone said the minimum should be 1200 but this makes a huges difference in file size. It just seems to increase the BR where it is not needed.

    Thanks
    The Min bitrate should only be an issue with some DVD players. For playback from the HD, use something low like 300.

    If you want to mess with different GOP structures and other encoding methods for minimising filesize whilst maintaining quality, take a look at some of the TmpGenc templates on www.kvcd.net
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  8. Originally Posted by bugster
    If you want to mess with different GOP structures and other encoding methods for minimising filesize whilst maintaining quality, take a look at some of the TmpGenc templates on www.kvcd.net

    Thanks, I really could not figure this site out.

    I increased the Max BR to 3400 and again the increase in file size was not that great. I have not tried to watch it yet but filesize was 830 MB.
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  9. Originally Posted by neo
    Originally Posted by bugster
    If you want to mess with different GOP structures and other encoding methods for minimising filesize whilst maintaining quality, take a look at some of the TmpGenc templates on www.kvcd.net

    Thanks, I really could not figure this site out.

    I increased the Max BR to 3400 and again the increase in file size was not that great. I have not tried to watch it yet but filesize was 830 MB.
    The mpeg-2 templates are Here . Not easy to find I will grant you.
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  10. I'm a Super Moderator johns0's Avatar
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    raise your cq to at least 70 to get better encoding.Mind you the file size will increase but that will give you better results than increasing the bitrate.
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