Video conversion :: irony

Hi,

The only windows machine I have access to is at work. I have used it extensively to convert DVDs to play on my son's Cowon A2 with no problems. However even the meizu supplied viceo converter when run on that machine cannot produce avi files that the M6 can play! Have tried virtualdub-mpeg2, iriverter and mediacoder on it as well and all failed.

In desperation I installed the converter from the meizu site onto a linux machine under wine and lo and behold the resulting avi files play on the M6.

I suspect this implies codec conflicts on the win system but have not managed to investigate this yet.

F

Thats odd... what codecs are you converting from?

btw: isnt there a conversion program for linux?

Stuff like this is my reason to stay with a Windows based PC. I know linux is free and better in many cases and Apple OX is good... yet they both often give problems in a Windows-rules world...

Originally Posted by Job

Thats odd... what codecs are you converting from?

btw: isnt there a conversion program for linux?

Stuff like this is my reason to stay with a Windows based PC. I know linux is free and better in many cases and Apple OX is good... yet they both often give problems in a Windows-rules world...

The avi files on the win xp machine have all been run through cowon's jet conversion software so heaven knows what they are encoded with. The initial rips were all done on linux using dvd::rip (which is excellent on the whole). If I could figure out how to get dvd::rip to rotate the outfile then life would be much easier. I did try a mencoder rotate but it messed up the sound. I have a feeling that iriverter will run under java on any machine but some of the jar archives are a bit obscure. Oddly the files created by the meizu converter under wine have perfect sound synch when played on the linux machines but not when played on the miniplayer (which I suspect implies a firmware issue)

You don't need to rotate file anymore ... it playes 320x240 as well as 240x320 ...

Originally Posted by Lolita

You don't need to rotate file anymore ... it playes 320x240 as well as 240x320 ...

I found that 320x240 384 kbs xvid, with 128k mp3 soundtrack videos stuttered when I played them unrotated. Having said which the activity level in the videos was very high (professional cycle race) which may have had an effect.

@Lolita: as far as I know you dont have to rotate the video but ist better to do so causeing less problems and using less power as the player doesnt have to rotate the video itself


@ scaglifr: I wish i was able to help you out. However, I have no exprience with linus based machines. I suspect its a codec issue though.

Well i tought so, but as i tested it more i think performance is same with rotated and unrotated video.

What about the syncing of video and audio in the movies..
are they the same for rotated and unrotated videos?

if so...i wont rotate my vids anymore!

Honestly, the reason the M6 plays video better rotated is for one reason only as far as I see, and it's pretty obvious: a smaller size video runs faster and loads frames faster... in other words, a video that is 320x240 would run slower than the same video rotated and scaled DOWN to fit as "240x180" because the rotated video is obviously smaller. Also, even if the video is still actually 320x240, the black area has nothing changing in it, so the file is only changing the digital pieces in that smaller section of the video... it's basically the same thing.

I am confused here

Wont 320x240 and 240x320 give the same file sizes with the same amount of data to process?

I am no expert on this so id like to know

Update ::

I uninstaled every single peice of video conversion software from the XP machine (taking all their codecs with them), then installed mediacoder alone and presto : playable files, rotated and reasonably sized. Must have been a codec conflict somewhere.

Sorrow : converted 2 discs using mediacoder in one run with same settings (both discs in same set and box), copied to miniplayer, one of them plays the other does not. Does anyone understand that ?

Well i don't really know either But this is how i convert movies
1.Convert you video file with Winemc
2. Reconvert it with Virtual Dub
3. Upload it to your meizu
And it works! ive had no problems with the sound being off tune with the voices.

I'm no expert, either, but I just use common sense to point out that the rotated video has smaller dimensions than if left alone because 320x240 width and height would be scaled down to 240x180. As for what I said about if it were still a 320x240 video with black filling in the blank area, then it has to do with the way mpeg compression works.

I remember reading an article about how it worked by breaking the video down into peices, which you can see sometimes with low quality vids where the picture breaks up into blocks. It had something to do with compression working by only using the data in the picture that changes from one frame to the next, and discarding the data that doesn't change, just reusing the same data from the last frame, or something like that. Since the black area would never change, it doesn't add much data, and since the area changing is a lot smaller, it can run faster and more fluidly.

A higher quality video with the same framerate is broken into more digital pieces, making unchanged blocks less noticeable during playback, but also raises the file size.

DChronos, rotating and scaling down are not the same. As Job said before, rotating a 320x240 video does just that: it rotates it to deliver a 240x320 video. There is no scaling down, no black bars get introduced, it just looks like it would if you would turn your head 90 degrees to the left. Rotated, not resized.

Maybe you need a visual to see, if you don't get it.

This is the normal video. Nothing changed in it.


This is the rotated video. Oh, look! Black bars! Weather they are there because the program input them there (Remember the "Fill Color=Black" option in the program?), or because there is nothing for the M6 to display there (like in the photo viewer), they are there.

As you can see, the video size is now 25% smaller than the full sized video. The black fill area does not make much of an impact on the ability for the M6 to play the video if it's still the same dimensions as a 320x240 video, because the actual part of the video that is playing is only 240x180 in size.

If the video was not scaled down, and was really only rotated, here's what you'd get. I don't think you would ever watch a rotated only video if this were the case:


EDIT: Oh, and ALSO... if the video was turned into a 240x320 video, like the last picture, but the M6 had to scale it down like it does with photographs, then, like what happens with photos, it will look sorta pixelated, plus the M6 would have to work harder downsizing the video to fit in it's screen, making it run slower.

OK...I am confused about who is right here... Dchronos or eriktous

I just tried a video i converted from 464x352 to 240x320.
The video plays with no black bars anywhere on screen

besides that...the fact is that a 240x320 files is the exact same size as 320x240 as it contains the same info with just the x and y axes flipped around... doesnt this mean its not downscaled?

I though the video gets rotated because the screen in the meizu is also placed rotated??

On the other hand...Dchronos's explanation seems logical...

Anyone to help us out here??

Before reading this I just knew I didnt know about it but thought I had a rough idea about how the meizu video option works.
After reading this I feel like a complete idiot.
I downloaded the Mini Video Engine 1.0 from the Meizu Page for the first run of encoding (as nearly everyone recommends 2 programs to be used I use VD afterwards) and this prog encodes to 240x320 as well.
Does that mean some part of this video is going to be cut of when playin on the miniplayer or that it still has to be downscaled by the player?
I mean, when MEIZU gives us this encoder with these fixed settings I guess they didnt do so just for the good crack to see people havin problems with it.
Or did I get it wrong that DChronos said videos should be encoded to 180x240?

feelin lost

I play my videos at 240x320 and they play full screen with no bars or loss as far as i can see

My understanding of the 320x240 / 240x320 question is that the screen is actually 240 wide x 320 high. (like a mobile phone screen) and data will be transmitted onto it in 320 lines of 240 pixels.

If you encode a video in 320x240 and not rotated (resulting in 240x320) then the software needs to make the change on the fly from sending 240 lines of 320 width to 320 lines of 240 width. This takes time and processor power which means it does not run as well.

Regarding encoding files and playback issues, over a period of my time with the M6 i've become very lazy! I now use a piece of software (recommended on this forum) called iRiverter. I have Meizu 15/18/20 fps profiles set in it, these profiles include the audio and video bitrate, and resolution. When I want to encode a file I simply select the file and press encode (it remembers the last profile in memory so I don't have to keep setting this). 20-30 minutes later I have an encoded 1 hour program.

As this is one pass encoding, I have noticed the following (but as I'm lazy it doesn't really bother me anymore):
1. Programs/films encoded by this method give the M6 problems if the final filesize or length of program are too high/long (over about 75 minutes starts to cause the file not to play - so I split my movies into chunks)
2. Audio starts ok but gets out of sync after about 30 minutes (stopping the program and restarting from the stop point using recent videos cures the sync problem)
3. The file is not rotated, so sometimes i get some pixelation (but like I say I'm lazy so not too bothered).

Having run quite a lot of conversions (I watch a lot of TV programs now through the M6) I've come to the following conclusion:
a. The M6 I think uses software rather than harware in some crucial part of the playback of avi's where other (more expensive) players use hardware. This is probably the cause of a number of the video problems everyone seems to experience.
b. I'm guessing that some sort of software buffer? is not clearing which causes some audio sync issues after some time, which is cured by starting the avi from part way through.
c. Having to encode more than once to get a more usable and stable file for the M6 indicates to me that M6 software is the issue, as single pass files play with no problem on other devices (PC/Mac/Cowon A2 etc.)
d. There are lot's of pieces of software out there based on mencoder, most are not for lazt sonbi*ches like me :-P However if you're prepared to suffer occassional restarts and don't want to mess around much with a program to encode files for the M6 then iRiverter is the easist i've found to use, however ones like Badak/pocket divx encoder/WinMEnc are all good, just with more bits on screen that may put off technophobes.

Ideally having used the M6 for some months now, what I'd really like to see is a slightly more expensive version, with a slightly larger screen and full hardware playback to complement this version.