Some newbie questions about avi(divx,xvid) and dvd

[inferno6a]

1. What advantages do frameserve has when building a vcd/svcd/dvd? is it necessary? [ANSWERED]

2. Is there any tool to check whether avi files are interlaced or progressive ( and whether its bottom or top field) ? I know dvd2avi do that for dvd files but that won't work for avi. or maybe... all avi files are progressive ?
[ I tried tmpegenc Plus 2.5 and Tmpgenc Xpress. both give me different results, tmpgenc xpress even detect a 23.XX fps video as 30 fps, so asking for other tools]

3. Will interlaced DVD looks fine on progressive TV?

4.
When encoding other formats to Avi files using divx there is settings like " balanced" " extreme quality " and such. One factor changed is the compression rate.

My question is when i switch from balanced setting which has a lower compression rate to extreme quality which has a higher compression rate,does that mean I can manually lower the bitrate setting while achieving the same quality as before when i use "balanced" setting?

Or do the higher compression rate means that I let the codec use the same bitrate but it will auto churn out a smaller file?

5. If I do not know whether a dvd is interlaced or progressive and i forced a already progresive video it to deinterlace by mistake when encoding it to avi using divx or xivd, will that mess up the show or will the result be as the original show?
[The divx/xvid encoder is smart enough to recoginse an already progressive show and leave it alone for eg]

6. What are some of the well known and quality encoders? I know Tmpgenc although Xpress really giving me problem and MainConcept Encoder. Any others?

7. will quality be lost when a progressive avi is converted into interlaced dvd? talking about quality lost because of P to interlace, not the general loss of quality during conversion

Thanks in advance.

[thecoalman]

This should asnwer many of your questions about intelacing and field order: https://www.videohelp.com/forum/viewtopic.php?t=257631

Not sure if it's adressed in that thread but if it's interlaced leave it interlaced if you intend on viewing the video on a regular TV. Deinterlacing interlaced does two things, deintelacing will remove detail. Additionally it will appear choppy on the TV.

[guns1inger]

1. Generally, avi files are not DVD compliant in resolution, display aspect ratio or pixel aspect ratio. This means that they will hve to be resized correctly first, and often have other filter applied as well. Frameserving allows you to apply a resize and other filters, then send the video data directly to your ecoder without having to go to the intermediate step of creating another file. As uncompressed video takes up huge amounts of disk space, a compressed format is the only viable alternative, which can only degrade your efforts. Frameserving avoids this.

2. With the exception of DV avi, most avi files are progressive. Divx and Xvid compressed files are almost always progressive. Unfortunately, most tools seem to mis-detect field order or progressive source anyway. The best way I have found to confirm if a file is interlaced is to load it into virtualdub, find a fast motion scene, and look for the tell tale combing effect that interlace produces on a progressive monitor.

3. Progressive televisions have built-in hardware deinterlacers. Interlaced footage will look fine on a progressive television. Hardware deinterlacers will always do a much better job of changing your footage on the fly than a software deinterlacer will when encoding. Software techniques generally result in either throwing away large amounts of information (often a whole field, or 50% of the visible video), or blur the fields producing soft output. If it's interlaced, leave it interlaced and let your TV do the hard yards for you.

4. Recompressing a video almost always lowers the quality. Even if a higher bitrate than the original is used, you cannot guarantee that the encoder isn't going to throw away more information on the second pass. How visible this is depends on many factors, including bitrate.

5. Some encoders only produce interlaced output, regardless of the source. If you are encoding for DVD, you may be allocating a slightly lower bitrate per frame because you have two fields instead, but the difference usually isn't noticeable.

6. CCE and Procoder are two highend encoders that produce very good quality output. Both are faster than tmpgenc, with CCE generally being the fastest of the lot. Neither are cheap, but both have consumer level versions (CCE Basic, Procoder Express). Main Concept license their encoder to third parties. Both Premiere and Vegas ship with tailored versions of the mainconcept encoder, and both of these generally produce much better quality output than the standalone version (a sad statement on Mainconcept's inhouse crew, really). There are also a number of freeware encoders worth checking out, including qenc (spelling ?) and HCenc. HCenc has had some good feedback, with some saying it is on par with CCE for quality, if not yet for speed. Again, the best quality will be obtained through careful use of avisynth or virtualdub to prepare the source before frameserving to the encoder.

[inferno6a]

got another question, does anything happen when a 29.97 framerate avi get encoded to PAL 25 fps dvd ? (smaller fps)
and when 23 fps avi get encoded to a larger fps dvd like 25 or 29.97 NTSC?

cause i notice choppiness when i encode a 29.97 to 25 fps Pal dvd.