Posted by Frank on 11/26/06 11:12

On 26 Nov 2006 01:13:36 -0800, in 'rec.video.production',
in article <Re: Exported AVi is of poor quality>,
pwilleke@gmail.com wrote:

>Hello,
>
>I used 2 AVI files as source for my Premiere project.
>This is what info I have about these two files:
>
>--------------------------------------------------------------------------------------------------------------------------------
>INPUT
>--------------------------------------------------------------------------------------------------------------------------------
>********************** Source File 1
>*************
>* GSpot *
>************
>* Size= 4.47 GB (or 4,581 MB or 4,691,504 KB or 4,804,100,856 bytes)
>* Audio
> - codec = PCM Audio
> - Stat: No Codec Required
> - Info: 32000Hz 1024 kb/s total (2 chnls)
>* Video
> - Codec: dvsd
> - Name: DVC/DV Video
> - Stat: Codec(s) are NOT Installed
>
>**************
>* Premiere *
>**************
>File Size: 4,47GB bytes
>Total Duration: 0:21:36:06
>Average Data Rate: 3,53MB per second
>Image Size: 720 x 576
>Pixel Depth: 24 bits
>Pixel Aspect Ratio: 1,067
>Frame Rate: 25,00 fps
>
>Audio: 32000 Hz - 16 bit - Stereo
>
>AVI File details:
>Contains 1 video track(s) and 1 audio track(s).
>
>Video track 1:
>Total duration is 0:21:36:06
>Size is 4,31GB bytes (average frame = 144,74KB bytes)
>This movie appears to have DROPPED FRAMES
>There are 32204 keyframes.
>There are 202 empty frames.
>Frame rate is 25,00 fps
>Frame size is 720 x 576
>Depth is 24 bits.
>Compressor: 'dvsd'
>
>Audio track 1:
>Size is 158,23MB bytes
>Rate is 32000 samples/sec, stereo
>Sample size is 16 bits
>Interleave: 25 frame(s)
>
>********************** Source File 2
>*************
>* GSpot *
>*************
>Size= 7.08 GB (or 7,256 MB or 7,430,851 KB or 7,609,192,024 bytes)
>* Audio
> - codec = PCM Audio
> - Stat: No Codec Required
> - Info: 32000Hz 1024 kb/s total (2 chnls)
>* Video
> - Codec: dvsd
> - Name: DVC/DV Video
> - Stat: Codec(s) are NOT Installed
>
>**************
>* Premiere *
>**************
>File Size: 7,08GB bytes
>Total Duration: 0:34:00:20
>Average Data Rate: 3,55MB per second
>Image Size: 720 x 576
>Pixel Depth: 24 bits
>Pixel Aspect Ratio: 1,067
>Frame Rate: 25,00 fps
>
>Audio: 32000 Hz - 16 bit - Stereo
>
>AVI File details:
>Contains 1 video track(s) and 1 audio track(s).
>
>Video track 1:
>Total duration is 0:34:00:20
>Size is 6,84GB bytes (average frame = 145,62KB bytes)
>There are 51020 keyframes.
>Frame rate is 25,00 fps
>Frame size is 720 x 576
>Depth is 24 bits.
>Compressor: 'dvsd'
>
>Audio track 1:
>Size is 249,12MB bytes
>Rate is 32000 samples/sec, stereo
>Sample size is 16 bits
>Interleave: 25 frame(s)
>
>
>--------------------------------------------------------------------------------------------------------------------------------
>OUTPUT
>--------------------------------------------------------------------------------------------------------------------------------
>The AVI file that was written when creating the movie in Premiere has
>the following info:
>* Size= 6.26 GB (or 6,418 MB or 6,572,568 KB or 6,730,310,644 bytes)
>* Audio
> - codec = PCM Audio
> - Stat: No Codec Required
> - Info: 48000Hz 96 kb/s total (2 chnls)
>* Video
> - Codec: cvid
> - Name: Cinepak by Supermac
> - Stat: Codec(s) are Installed
>
>
>That is a lot of info for me, but I hope you guys can tell me morer
>with this.
>I hope I don't have te create my project all over, I couldn't. But
>instead I hope to improve the quality in some other way!
>
>
>Regards,
>P


With regard to your input files, they both appear to be standard PAL
DV (Digital Video) files, but with low quality 16/32 audio rather than
16/48 audio.

I have no idea why GSpot reported that you didn't have the correct
video codec installed, as a DirectShow-based version is included with
Windows (MSDV.SYS). You might want to check (run DXDIAG.EXE) to ensure
that you have the latest version of DirectX installed (9.0c) on your
system. If you don't, then get it from the Microsoft Web site.

When you created your output file, it looks like Premiere upsampled
your audio from 16/32 to 16/48. There's nothing wrong with this. In
fact, in the future, always acquire (shoot) your video with 16/48
audio to start with, not 16/32. 16/32 is garbage.

As to the visual quality of your output file, it looks bad because it
was encoded with the Cinepak codec, which is sort of old and obsolete.
Also, we don't know the frame rate and frame size (dimensions) of your
output video file because this information isn't listed in your post.
This is critical information.

When you saved your output file, you should have specified DV as your
output codec. I suspect that Cinepak was chosen because it may be the
default codec on your system and you didn't specify anything to the
contrary.

I also get the feeling that you're using an old version of Premiere
and not the latest Premiere Pro 2.0, but for a project like this, that
should have no negative impact, although you have to be careful which
codecs you select.

I also have a suspicion that the output file that you created may have
a frame rate as low as 15 frames per second instead of 25 frames per
second and that the frame size may be as small as 320 by 240 instead
of 720 by 576.

Sorry to say this, but there's no way to recover the lost visual
quality at this point. You will most likely have to re-edit your
project.

As a quick test, you may want to open up one of your two input
(source) files in Premiere, edit out a small one minute portion, and
save this one-minute clip back out to disk (under a different name, of
course - do not overwrite the original file) specifying the DV codec.
Then open this output file in GSpot to ensure that Premiere used the
DV codec (FourCC dvsd) at 25 fps and 720x576 and that the audio is
2-channel 16/48 PCM.

In other words, ensure that you have the correct workflow in place
prior to doing an actual project.

Also, I don't know which version of Premiere you're using, but you may
want to start by creating a Project which has the correct parameters.
Then import your source files, edit, and render your output file.

Good luck.

--
Frank, Independent Consultant, New York, NY
[Please remove 'nojunkmail.' from address to reply via e-mail.]
Read Frank's thoughts on HDV at http://www.humanvalues.net/hdv/

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