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25th February 2002, 15:43 | #1 | Link |
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Maximum bitrate question
I found in some SVCD guides that max video svcd bitrate is 2600, and in a thread posted here (can't remember wich one) I saw something about a 2350 (or something approaching) max bitrate !
What's the real max video bitrate for an SVCD ? |
25th February 2002, 16:04 | #2 | Link |
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it really depends on your stand alone player. you can check vcdhelp.com to see what's known about yours.
2600 sounds more like max total bitrate
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25th February 2002, 18:03 | #6 | Link |
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hey dude...2600max for an SVCD player...do you have an SVCD player?
I'm sure you have a DVD player can handle MUCH more than 2600Kbps, now if someone would only anser question 2 of my thread a couple days ago: http://forum.doom9.org/showthread.php?s=&threadid=17979
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25th February 2002, 18:18 | #7 | Link |
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No, I don't have an SVCD player, but bitrate issues can cause playback problems (you should know, because it's what happened you when you tried using a 8000 bitrate as you said in your thread).
I just want to stay compliant with the standard so my SVCD will play correctly on most players. |
25th February 2002, 18:31 | #8 | Link |
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yeah I did try 4500Kbps and that worked well, I just know the maximum for the DVD player and prolly most will be somewhere in that range
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25th February 2002, 19:37 | #9 | Link |
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Max bitrate as described in the standard of SVCD has some "flavors":
maximum VIDEO ALONE is 2600 maxumum AUDIO ALONE (all audio streams combined) is 384 Maximum TOTAL (audio+video+subtitles+whatever) is 2748 if your audio is at 224, your video can be as high as 2524, but since in multiplexing some space (-> bitrate) is wasted, it is slightly lower (perhaps 2510...). You can calculate the exact value with the utility "FitCD" that you can download from doom9.org if your audio is at 112, your video could be at 2636, but since the video cannot be higher than 2600, that is the maximum. If you want to have 2 audio streams at 224, bad luck, because you cannot: 224+224=448; maximum for audio is 384. It can be 224+160, or 192+192 or many other combinations, but 224+224 is forbidden. Of course, all that is what the standard says... I think, unless you have some very specific reasons, you should stick to the standard; some players cannot reach the standard, but that are players that should be avoided. Your encodes should not be handicapped because somewhere in the world some guy has a junk player that can only reach 2000Kbps bitrate maximum, don't you think? And also, you should not go further than the standard, perhaps the player you have today can play to 3000Kbps, but many other cannot; the standard exists precisely to have a common ground for everyone. Last edited by Pko; 25th February 2002 at 19:41. |
27th February 2002, 21:47 | #11 | Link |
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In regards to having 2 audio streams at 224kbits, I think thats still within the standard. I believe that the max audio bitrate of 384kbits only applies to a single stream.
Svcd standard bitrate limits for both video and audio were derived from the speed at which the data could be read from a cd, ie: 2x. Even if the cd contains audio which adds up to more than 384kbits, its still only playing, in this case, 224kbits of audio at any given time. I may be completely wrong about this but with 2 audio streams at 224kbits Philips SVCD Verifier still says it complies to the SVCD standard, and I've never found a dvd player which couldn't handle it. Ultimately I guess it really doesn't matter either way since the svcd standard appears to be anything BUT standard. If it plays on your dvd player than thats really all that matters, just don't go too crazy. |
28th February 2002, 05:20 | #12 | Link |
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I looked at a DVD I had with Kenshin on it and did some math:
For a 23 minute episode the entire vob's were 1500mb/episode With that plugged into DV tool with two audio sources it came out to around 7000Kbps, so that means most DVD players can go at least that high. It would stand to reason that it would be able to read SVCD's at that high, or at least above 4000 which makes SVCD's look perfect.
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28th February 2002, 13:32 | #14 | Link |
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Most DVD players can't read CDR as fast as DVD. The entire laser mechanism is tuned (mechanically and optically) to read DVDs. Plus the fact that, at a given angular speed, more data will move under the laser pick on a DVD than on a CDR.
So, bottom line, few DVD players will be able read 9.8 mbps from CRD, and many won't even read 4.0 mbps (I know my apex won't - I can't even do 3.0 mbps reliably). @ebert - I believe it is the maximum that you need to worry about for playability. If the max goes above what your player can read (except for maybe very short bursts), you'll get playback problems. |
28th February 2002, 14:14 | #15 | Link | |
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Quote:
But as you said, if all the players play it, it is a moot point :-) I think that the audio limitations are not very important, because what SVCD is usually crying for is VIDEO bitrate. For example, the 128 audio is (IMO) usually less annoying than the 2600 video... and 2600 is as high as you can go while 128 is a middle setting. I've seen professional DVDs that had MP2 at 224 while the video went at 4000-6000! MP2 at 192 is usual in DVB too, and the video there is in the 3000-5000 range. |
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28th February 2002, 19:07 | #17 | Link |
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specs
If you would:
http://www.cdrinfo.com/articles/svcd/ is _the_ link describing the official specs... In brief: audio: between 64 and 384 kbit/sec, video: up till 2600 kbit/sec, however: total bitrate should not exceed 2.8 Mbit/sec. It'll also explain the whole thing with the svcd scan offsets, and those infamous underflow errors you can get with bbmpeg muxing. Something I wonder: this document states: audio bitrate: may vary from frame to frame. Does this mean you can create variable bitrate audio for svcd too? |
28th February 2002, 21:00 | #19 | Link | ||
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Quote:
Quote:
I usually encode with cce and find that when I set a certain bitrate as maximum, after checking it with bitrate viewer the stream almost always exceeds this maximum by a quite big amount during complex scenes. Thus, I keep my max bitrate setting at 2400 maximum. This way it almost never goes above 2600... |
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1st March 2002, 15:01 | #20 | Link | |
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Re: specs
Quote:
I plan to do some tests soon. I'm also planning to do some new SVCD tests disks with "advanced" features: - VBR audio - Subtitles (SVCD, CVD and both mixed) - Silent HQ still menues, HQ still menus with sound, moving menus - Chapters - Mixed PAL/NTSC/FILM streams - Non-compliant streams (352x480/576, 48KHz audio, peaks going over standard) The idea is have some SVCD images to test, so people can download them and report what works and what not (something like "svcdtest3, second stream works, third stream does not on player brand XXXXX model YYY"). So there would be a common ground to compare everything. One of the things that stops me from preparing them is that I need some decent quality source videos/audios that must be totally copyright free... |
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