AnimeSuki Forums

lalala123 · 2007-11-07, 23:29

I have been trying to covert some fansubs to a smaller file to play on my PMP.

The files that I first tried to use were these two.

All the settings that I used were the same. The only noticeable difference between the two original files was the Video BitRate.

Here is the results of the finished product.

Why is it that there is a suck difference in the ending file size?

The only thing that i see is that the Data Rate for Eps 1 is 56kbps and 80kbps for the Eps2

Is the difference in file size related to the Data Rate?

How can i change the Data Rate wile compressing the files?

P.S
The Portable Media Player I have has a 4" wide screen

It is cable of playing .avi, DIVX, XVID files. with max resolution of 720x480 @ 30F/PS

I want the smallest possible file size when compressed but with none to little lose of quality compare to the original fansub.

What is the best setting when decompressing file to best fit my player with no wast.

thanks allot

WanderingKnight · 2007-11-07, 23:50

Quote:

The only thing that i see is that the Data Rate for Eps 1 is 56kbps and 80kbps for the Eps2

Is the difference in file size related to the Data Rate?

You've answered your own question. I can't help you much because I don't know much about encoding, but "kbps" means "kilobytes per second", which indicates how many kilobytes of data are to be found in a single second of the stream. The more kilobytes per second there are, the more total kilobytes the file will have. More kilobytes = bigger size.

Ledgem · 2007-11-07, 23:59

WanderingKnight hit it exactly. We take animation for granted, but think about it this way: each frame is an image. As a standard, we have 29.97 frames per second. That adds up quite a bit over time! The longer the video, the greater a difference you'd notice in file size.

As I said, we take our codecs and relatively low filesizes for granted. I remember being shocked when working with raw, uncompressed video - a ~30 second clip was over 1 GB in size!

SeijiSensei · 2007-11-08, 07:56

I think the question lalala wants answered is why the files differ in size despite having no differences in the encoding settings. I'd like to know that myself. The initial files to be converted have nearly identical bitrates, and the application is set to use the same 700 kbps rate for the encoding. You'd think the resulting files would thus have the same bitrates and the same sizes. In fact, they don't.

I don't see any setting to force it to use two-pass XviD encoding. Usually that helps a lot with the management of bitrates and file sizes. Perhaps this application does two-pass encoding by default, or perhaps you need to select that method somewhere else? See if you can force it to use the two-pass method.

martino · 2007-11-08, 08:22

It seems like the application that you are using doesn't reveal quite an important setting, that being the quantizers. It's usually the quantizer settings that specify as to how much a frame is to be compressed (the smaller the less compression). If you want to hit a specific bitrate quite precisely then you should use I/P/B-frame quantizers at 1/1/2. You can also try 1/2/2 since P-frames rarely use a 1 quantizer but you'll most likely get a smaller filesize than what you wanted, however this depends a lot on the source. In this case it looks like the application uses 1/1/1 which just results in a waste of bitrate and a bigger file than what you aimed for by giving the bitrate setting. The XviD VfW encoder and also xvid_encraw through MeGUI allow you to specify these settings.

What other options are there for the video quality levels?

(Note: 700kbps seems to be a bit high for the resolution that you are aiming for)

2007-11-07, 23:29	Link #1
lalala123 Junior Member Join Date: Nov 2006	Difference in File size! I have been trying to covert some fansubs to a smaller file to play on my PMP. The files that I first tried to use were these two. All the settings that I used were the same. The only noticeable difference between the two original files was the Video BitRate. Here is the results of the finished product. Why is it that there is a suck difference in the ending file size? The only thing that i see is that the Data Rate for Eps 1 is 56kbps and 80kbps for the Eps2 Is the difference in file size related to the Data Rate? How can i change the Data Rate wile compressing the files? P.S The Portable Media Player I have has a 4" wide screen It is cable of playing .avi, DIVX, XVID files. with max resolution of 720x480 @ 30F/PS I want the smallest possible file size when compressed but with none to little lose of quality compare to the original fansub. What is the best setting when decompressing file to best fit my player with no wast. thanks allot

2007-11-07, 23:59	Link #3
Ledgem Love Yourself Join Date: Mar 2003 Location: Northeast USA Age: 38	WanderingKnight hit it exactly. We take animation for granted, but think about it this way: each frame is an image. As a standard, we have 29.97 frames per second. That adds up quite a bit over time! The longer the video, the greater a difference you'd notice in file size. As I said, we take our codecs and relatively low filesizes for granted. I remember being shocked when working with raw, uncompressed video - a ~30 second clip was over 1 GB in size! __________________

2007-11-08, 07:56	Link #4
SeijiSensei AS Oji-kun Join Date: Nov 2006 Age: 74	I think the question lalala wants answered is why the files differ in size despite having no differences in the encoding settings. I'd like to know that myself. The initial files to be converted have nearly identical bitrates, and the application is set to use the same 700 kbps rate for the encoding. You'd think the resulting files would thus have the same bitrates and the same sizes. In fact, they don't. I don't see any setting to force it to use two-pass XviD encoding. Usually that helps a lot with the management of bitrates and file sizes. Perhaps this application does two-pass encoding by default, or perhaps you need to select that method somewhere else? See if you can force it to use the two-pass method. __________________ Taking Anime Seriously - Politics by the Numbers - Sports by the Numbers - MAL List - Avatars - Images

2007-11-08, 08:22	Link #5
martino makes no files now Join Date: May 2006	It seems like the application that you are using doesn't reveal quite an important setting, that being the quantizers. It's usually the quantizer settings that specify as to how much a frame is to be compressed (the smaller the less compression). If you want to hit a specific bitrate quite precisely then you should use I/P/B-frame quantizers at 1/1/2. You can also try 1/2/2 since P-frames rarely use a 1 quantizer but you'll most likely get a smaller filesize than what you wanted, however this depends a lot on the source. In this case it looks like the application uses 1/1/1 which just results in a waste of bitrate and a bigger file than what you aimed for by giving the bitrate setting. The XviD VfW encoder and also xvid_encraw through MeGUI allow you to specify these settings. What other options are there for the video quality levels? (Note: 700kbps seems to be a bit high for the resolution that you are aiming for) __________________ "Light and shadow don't battle each other, because they're two sides of the same coin"