Codec question

djphenominal

Just a quick question, i am using visual hub to convert my vob files to mp4. Mix emergency gives me the following message " Warning you may experience poor performance using this video codec " Any idea why ? Thanks, Alex.

Nick

What is the extension of the file? (if it's m4v, can you try renaming it to mp4 and trying it again?) Do you know what codec you are using to compress the files with?

djphenominal

Sorry. I forgot to give details. The files are in mp4 format. As far as the codec goes I have no clue. I simply installed visual hub, made some changes to the settings as told to on the serato forum and converted. They work fine but the error message makes me a little nervous.

Nick

Yeah, if you're getting that warning message you will experience lower frame rates than normal (i.e. perhaps 30 FPS instead of 60 FPS). I recommend converting videos using the new HandBrake (0.9.3) application: http://handbrake.fr/ If you use HandBrake, try the Normal preset - and then add the option "keyint=25" to the options in the Advanced tab. You will also want to set the bitrate to somewhere between 1500 - 2000 (or more) kbps. Though these output an m4v file which currently needs to be renamed to mp4. Otherwise we can look into your file problems some more - perhaps you could let me know exactly what settings you are using in VisualHub?

djphenominal

If i where to use hand brake, would renaming from m4v to mp4 be as simple as "renaming" from .M4V to .MP4 And if so, is the the newly renamed file a true MP4 that i can play on both mac and pc ?

Nick

As far as I am aware, the m4v extension is supposed to be used for raw mpeg-4 video streams. The files that you are producing most likely contain a video stream and an audio stream, and so you should be able to rename them to mp4 (i.e. they will actually already be an mp4 container). I think this issue comes from Apple incorrectly using the extension for their iPod/iTunes files.

djphenominal

Cool. I will give it a try. Actually i just realized that hand brake can be run on PC as well, so i might do all my converting on my and then copy the converted files to my mac external.

djphenominal

Hey Nick, i had little luck with hand brake. I did however realize that i have super installed on my PC, after some minor tweaking i was able to convert a couple of VOB files to MP4 with very little loss in video quality and all audio and video files fully synced . Thanks for your help on that matter. On another note, most of the videos i use are either promo-only which are the ones i have to convert. The rest are from smashvidz and come in MP4 format, with these videos i got a message stating - " Warning : Distance between key frames is greater than recommended " I checked the FPS on these videos and saw that they are set to 23.976 As a test i ran these through super changing only the fps to 29.97 and no longer got a warning message. Wondering if i should worry and re-encode these files as well or if they will play fine. I can send you some of the files for testing if you'd like. Thanks in advance, Alex.

Nick

The "Warning: Distance between key frames is greater than recommended" refers to the Key frame distance, not the number of frames per second (FPS). You can read about Key frames here: http://en.wikipedia.org/wiki/Key_frame (the last paragraphs on the page under the "Video compression" title). The reason that the message has stopped will be from the fact that Super has inserted more (i.e. closer together) Key frames than the videos were encoded with previously. If you have your cache level set to around 1 GB you may not notice any effect from the key frame distance of your Smashvidz videos - but if you would like faster random access in the files you should re-compress them.

djphenominal

Cool, thank you . Excuse my ignorance in this video thing, i am new to it and still don't know my a$$ from my elbows . Has anyone encountered any trouble from the smashvidz videos that you're aware of ? Do the specs of the machine have anything to do with it ? I would hate to re-encode everything unless necessary, but i would rather tackle this now all in one shot if it has to be done. Thanks again, Alex.

Nick

Not that I'm aware of. I think that you should see how it goes using a large cache size (around 1 GB) in MixEmergency.

Mambomuziki

DjPhenominal, What setting are you using on Super, I used to use super but all my videos showed error "Distance between keyframes....) I changed to Mediacoder which is pretty good but a bit slow. Another thing I have noticed is all the videos you get i.e from subscriptions like smashvidz, and are in mp4 format have to be re-encoded with settings to avoid the keyframe issues.

djphenominal

Mambomuziki, Give me a bit to get this info. for you. After testing and getting good results with super i decided to upgrade to their new version which is not working properly. then tried re-installing the old version with no success. Once i get it working i will post my settings.

djphenominal

Hey Nick, After roughly a week of scouring the internet for different options in video conversion i went full 360 and landed back at hand brake. I tried again with a bit more patience and have been able to figure the software out. My only concern is that no matter what i set the key frame to i still get the warning message. I went as low as 5 in the hand brake advanced setting for key frame and still got the error message. Any ideas as to why this is happening ? It does not seem the affect the softwares performance, just seeing the error icon unnerves me a bit. If u feel that is nothing to worry about i will start converting tomorrow. If u like i can send u a copy of the file i tested with for you to analyze. Thanks in advance, Alex.

Nick

What is the "Video Codec" popup menu set to in HandBrake? And have you added a colon before the you added the keyframe interval in the advanced panel? (i.e. ":keyint=25")

djphenominal

codec is " h.264 (x264) " The colon is there before the command ":keyint=25" I also tried a preset for hand brake by serato that further tweaks hand brake and still same key frame warning. Serato's preset sets the key frame to 10 and i myself in normal mode went down to 5. Overall everything seems to run smooth. Just wondering if there is something i am missing or if i am running a risk by playing live with videos that give this message .

Mambomuziki

Dj Phenominal, If you have a PC on the side I would recommend Mediacoder, Use the following settings, under video: *mp4 *2 pass 3000kbps crucial->change to Baseline Level 1.0 (change quality to 100) *format- h264 (change the setting to be 'max & min interval between IDR frame=12 *source- auto select (which is ffmpeg x264) *encoder- auto select under audio: *source- auto select *encoder- faac (container aac) *avg bitrate 160 low complexity under picture: *resize- 640x480 *framerate- 29.97 (global) then in 'picture' menu click on effects: check- deblocking, deringing, yadif 0 (best deinterlacer) and at this point you can make the video darker sharper, all that. and under the audio menu you can normalize or boast the gain for those low audio videos... best thing about this program is the audio and video sync up better than any converter i've seen. i don't know how to post files but if somone schools me i can post up 'my mediacoder preset' ******The above configuration is quoted from "http://www.scratchlive.net/forum/discussion/?discussion_id=87630#1234580". It works for me and the results are great( for the time) Cheers

djphenominal

thank u mambo. my next step was to ask u ur settings for media coder. i tried it but was not sure of the settings and it kept crashing on me. i will try it tonight with those settings. thanks again

djphenominal

Hey mambomuziki, i tried media coder with most of the settings above. I could not find this " crucial->change to Baseline Level 1.0 " I tried converting 2 videos and all started good but eventually gave me a error message in the status box.

Mambomuziki

Dj Phenominal, Make sure you are using the latest version which should be 0.6.2.4226, click on the video tab (just below the task screen-on the left), then on your right click on X264, under profile you should be able to scroll down and find Baseline, Please PM and I will send you a screen shot. Cheers.