YouTube - Key Frames, Data Rate, Encoding

All of my shooting is 16:9 and a great deal of that uploaded to YouTube. Having said that, their recommendation is MPEG4 (Divx, Xvid) format. Having said that, I do not see either Divx or Xvid as an option within FCE4. Any suggestions?
Also, when preparing videos for the Internet any help on the following would be greatly appreciated:
(1) Should one select "Prepare for Internet Streaming, Fast Start"?
(2) Key Frames (default is 24)
(3) Data Rate (defauls to 6400 kbits/sec)
Any recommendations for the above?
As always, thanks.
Lyman

The Divx codec is an purchased addon (demo is available for use xx days), though you may find that video being uploaded to YouTube using any codec may show little or no difference.
Searching the forum would have found a number of discussions, see here for one of them http://discussions.apple.com/message.jspa?messageID=6241782#6241782
Good luck.

Similar Messages

Multiclip Dropped Frames/Data Rates from from FW 800, 7200rpm Drive

I am using an external Lacie 7200 rpm "Little Big Disk" .. Editing DV Multiclips in Final Cut (3.6 MB/sec data rate per clip... 7 clips/streams) But it won't play back all at once, anything over 15 MB/sec data transfer rate (as I watch Activity Monitor) it starts choking and dropping frames til it just freezes. Lacie claims that this drive handles a steady 80MB/sec transfer rate... All I need to do all these streams is 26 MB/sec (That's the speed it does at work from an XSAN and no problem playing back 7 streams of DV) Is the bog down in my system the FW800, my RAM, processor, or the Cache of the drive? (16MB)

Do you have any other FireWire devices (incl. cameras) plugged into other ports on the computer or on the drive itself? There's only one FireWire bus on a G5, and it's shared between the FW800 port and the FW400 port on the back in addition to the FW400 port on the front.
If you have other devices plugged in, they can cause the entire bus to slow down to the speed of the slowest connected device.

Key frame data Losses

Hi all
I sent a Sequence from FCP to Color and grade my shots. I create a vintage and I keyframe it. I save my project and later I reopen that project, the keyframe data no longer to be there. I did it three times. But the same. Why this happen. Please Help
Anup

Hi Anup. I use the grade tools in fcp myself. But I guess the problem might be you saved the project in color, then next time you opened from fcp. If I am right search finder and you'll have two project files saved!
John. Www.tripleumovies.com

Best Data Rate for Export to DVD as Quicktime Movie

Hello - hope someone out there can help me!!!
I put together a slideshow for my high school reunion using iMovie HD 5.0.2 and need help with settings exporting it as a Quicktime movie.
*I want to export it to a DVD* so that I can play it on a friend's laptop and I'm not sure if iDVD would be the way to go - my friend has a Macbook Pro I can borrow so it might be okay - I am worried about the fact that I've been working on older software. (I have read about opening iDVD and bringing in iMovie project vs. "share to iDVD"). So they suggested instead of iDVD I just export as a quicktime. Then I can burn it in Toast (v.6.0.2)
Wondering about *BEST DATA RATE?*
In export settings I have:
compressor set at H.264
frame rate: current (should that be DV-NTSC?)
key frames: automatic (?)
encoding: best quality/multi-pass
should data rate be automatic?
Some details that might be relevant to helping me:
*Stills brought in as clips with cross-dissolves, only two uses of "Ken Burns effect"
*Some stills were in the project from my LAST reunion - I realize I should have reimported all the stills since I am now recompressing them, but it's too late now!
*no audio
*Slideshow is about 45 mins long, file size says 5.52GB although when I looked into exporting it last night it said 9+GB - not sure why
*Using a G4 Tower (not my ancient laptop) with OS 10.4.11, Dual 533MHz PowerPC, 1.5GB SDRAM
iDVD version is 6.0.4
please help if you can!! thank you in advance...

Are you trying to burn a standard DVD or are you trying to put a QuickTime .mov file on DVD media?
A standard DVD doesn't worry about file size (only the duration).
A "data" DVD is limited to the type of media used. A single layer DVD is about 3.7 GB's.
In order to make a data DVD you need to keep the data rate low enough to not exceed the DVD media playback abilities. They can't handle the higher rates found in many of the preset options.
You can avoid all of these headaches by telling the viewer to "copy" the .mov file from the DVD to their Desktop. Then nearly any of the presets option will work.
H.264 is a great video codec and the "automatic" preset should work just fine. Use "multi-pass" for best quality (takes a very long time). Remove the check mark for "Audio" since your file has none. Leave it checked and you waste file size because a silent audio track would be added.

H.264 data rate difference between local and distributed encode

Doing some testing today and noticed this curious behavior with compressor 3.5.1:
Set video encode for a 50 second 1080i uncompressed file to H.264 at 50000 kbps (50 mbps). Audio is 24 bit, 48khz stereo with no compression.
1. Sending the job to "This computer" for a local-only encode gives me a file size of 327 MB
2. Sending the same job to the same computer using distributed encoding gives me a file size of 211 MB
The data rate for the distributed encoded file is about 34 mbps, which isn't what was specified in the encode settings in Compressor. The data rate for the locally encoded file is about 52 mbps, which is what I would expect when the audio is taken into account.
Why the difference? Both encoded files are the same duration, so there aren't any missing frames. They both look good and play well but this is giving me cause for pause.
Also, another curious difference I noticed... The distributed file has the More Info fields populated with useful information in the Finder (dimensions, codecs, duration, channel count, total bit rate). The locally encoded file does not have this information.
-Matt

Hi,
Not sure if this can be corrected whit customizing. Please see SAP note 1065932 for background on currencies in asset accounting. Some explanations on differences in currencies can be found there.
Regards,
Andre

Bad key frame artifacts with preset mobile encode settings.

AME CS6 encodes very poor quality low bitrate encodes (when we choose any of the mobile h.264 presets). There is noticeable key frame artifacts about once every second.
In contrast, the free Handbrake program has been able to encode great video since its early versions a few years back.
I didn't expect such poor quality from a product which cost so much.
Will Adobe tweak the presets properly to produce DECENT low bit rate videos please?

That request is best made directly to Adobe, rather than in a user forum.
https://www.adobe.com/cfusion/mmform/index.cfm?name=wishform

Frames rates encode to audio files

Hello,
I am not a Soundtrack pro user nor a Final cut pro user, (I use REAPER, and other audio programs); however, I got two people who called me asking (because I am apparently there only audio person they know) "how to change the frame rate on audio already recorded?" One person used the zoom H4N, and the other used a MAudio (?) recorder.. I looked them up and there is no encode to match the frame rate of the film to the sound. It seems that both recorders have no function to do frame rate encoding. (film speed was 24 frames not 30 frames.)
Is there a function to change the audio encode to match the frame rate of the film with in these programs?
What I know is sound is sound; 10 min of footage equals 10 min of audio. It is the encode that tells the film edit tool this is to match 24 frame or 30 frame.
I have looked into the manuals (table of contents) of Final cut pro and Soundtrack pro and not found the key words "Frame rate change to audio files" or "encode to audio files for frame rate"... I also looked online with the words "Frame rate change for Audio files" and "Audio encode frame rate change."
Can anyone help me to pass this information back to these people?
Thank you!

Tell them to change the sample rate to 48khz/16bit. Straight audio does not have a frame rate.
x

Is there a way for the tracker to do key frames at the frame rate of the comp setting?

I was doing some tracking in a 24fps project (yes my comp settings are correct) and I was really annoyed to see that the track looked to be generating key frames at 29.98fps. Of course this means crazy jittering.
Is there a way I can change the rate that tracker generates key frames?
Please help. I use CS3.
Thank you in advance for your help.

Mylenium said this:
> Is the footage interpreted correctly? There has been some
> discussion for CS4 about incorrect frame rate treatments in
> pretty much all of Adobe's video-centric tools, but I'm not
> aware of any particular issues with the tracker. Still, maybe
> it is one of those bugs.
redmike said this:
> I was doing some tracking in a 24fps project (yes my comp settings
> are correct) and I was really annoyed to see that the track looked > to be generating key frames at 29.98fps. Of course this means crazy
> jittering.
(I assume that you mean 29.97, not 29.98.)
In all versions of After Effects, the motion-tracking keyframes are set at the frame rate of the footage item on which the layer is based, not at the composition's frame rate.
Have you checked to see that your footage item is interpreted to be 24fps?
Also, are you sure that this "jittering" that you're seeing is because of the rate of the motion-tracking keyframes?

Encoded video does not have expected data rate

Hi
I've been encoding with Flash Media Encoder (CS3) recently
and come across a contradiction which I can't seem to make sense
of. Can it be possible that the longer the video, the harder it is
for the encoder to maintain data rate?
This was revealed when I started using FMS2 (space on a
shared server as opposed to my own server). I encoded a video at
what I thought was a data rate which was within my data rate limit
for my stream and it stuttered on playback over the stream. The FMS
supplier informed me that the FLV I thought I'd encoded at 400kbps
video 96 kbps audio actually had a data rate of around 700kbps in
total. But if I open the video in a FLV player, and look at info,
it still shows the setting I originally intended. However, my
supplier suggested checking data rate using this equation:
(filesize in MB x 8)/videoduration in seconds = video
datarate in kbits/sec
If you apply this calculation to my video it does indeed show
what they said:
Using Flash Media Encoder:
Encoded at 400kbps video - 96 kbps audio
Compressed filesize = 26,517 kbytes
Duration = 240 seconds
CALCULATION GIVES DATE RATE OF 880k/b a second
(note file contains an alpha channel)
Furthermore, applied to a shorter video, we get the following
more logical results:
Encoded at 400kbps video - 96 kbps audio
Compressed filesize = 6,076 kbytes
Duration = 90 seconds
CALCULATION GIVES DATA RATE OF 527 kb/sec
(no alpha channel)
The only differences between the two vids is the alpha
channel and the duration. Somethings doesn't add up here.
Any clues?
Thanks
Simon

I've just partly answered my own question. Funny how writing
a post can help you think your problem through sometimes.
The issue is the alpha channel, which adds to the file size
thereby making the data rate "incorrect". In other words, the same
file encoded without the alpha channel provides the expected
results. I guess this changes my question to: How do I create
predicatable data rates when encoding using an alpha channel. I
could just estimate of course and see what comes out, but is there
a better way?
SImon.

Quick Notation Question - Data Rates/Frame Rates/Interlacing

Finally upgraded to a decent prosumer camera and I'm trying to decipher what the manual is telling me about the many different formats it shoots and and the associated options. I keep seeing things like "There are two basic shooting modes: 720p and 1080i/p.", which I'm finding confusing. In my understanding, the "p" in 720p means progressive video and the "i" in 1080i means interlaced. So what do I make of 1080i/p?
On top of this, my camera shoots in "native" mode, which drops duplicate frames used in "over 60" formats. This will give me variations in the notation like:
720/24pN
720p Native 60 fps
1080i/24p
1080/24PN
Can someone give me a quick primer about frame rate vs data rate and explain how to read these notations? I'd appreciate it quite a bit.
Thanks!

There are so many cameras, capable of so many different formats that providing a manufacturer and model could be helpful in this discussion.
Jim's answer is absolutely correct but I'm going to re-state for clarification.
The i/p designation means you can chose to record as interlaced or progressive for a given resolution.
It sounds like your camera is designed to "capture" images at 60 frames per second, selecting "native" mode means extra frames are deleted and only the desired frames, based on frame rate setting, are recorded to memory. The advantage of "native" @ 24fps is you save space on your memory card. The advantage of NOT using "native" mode is that all 60 frames per second are recorded, but the file metedata tells playback software to only show the frames needed for the specified frame rate (i.e. 24). Since all 60 frames per second are recorded, you use more memory but you also have the option of retrieving all the those frames, if you so desire, at a later time (i.e. for smoother slo-mo).
To be honest I don't know what your spec of 1080i/24p means. If that is truly an option then I would guess it means it will record a 24p image but the metedata would indicate the file should playback at 30fps interlaced by adding the proper 3:2 pulldown. This would give you that "film" look in a broadcast compatible format.
For the most part, you don't want use use any interlaced settings. Very few display devices still in use can properly display interlaced images. Interlacing is only required in some broadcast specifications.
To answer the second part of your question;
Frame rates are an indication of how many times the moving image is captured over a given period (per second). Higher frame rates means smoother, more "real life" motion. Data rates can generally be considered an indication of image or audio quality. Higher levels of compression result in lower data rates and (generally) lower quality. If squeezing more hours of footage on fewer memory cards is more important than getting the best image quality, choose a lower data rate. Higher frame rates (more images per second) inherently require a higher data rate to retain the same quality as fewer frames at a lower data rate.

H.264 All-Intra Data Rates Significantly Higher

Does the built-in H.264 codec encode I-frame only files differently? I am trying to determine the optimal GOP length for high bitrate exports. Image quality seems to degrade, even in the I-frames, when using key frame distances greater than one.
After performing a series of tests to characterize the Adobe H.264 encoder, I discovered that exported files are significantly larger when key frame distance equals one frame (N=1). The average video data rate for a test file rendered with the Adobe H.264 encoder is as follows:
N=1 : 2.17 bpp : 24I
N=2 : 0.66 bpp : 12I + 12P
N=3 : 0.59 bpp : 8I + 8B + 8P
Note how the data rate drops 70% (from 2.17 to 0.66 bpp) even though 50% of the I-frames still exist when N=2. By comparison, here is the video data rate when exporting with QuickTime H.264:
N=1 : 0.89 bpp : 24I
N=2 : 0.70 bpp : 12I + 12P
N=3 : 0.64 bpp : 8I + 16P
The following chart shows data rates at key frame distances from 1-48 frames for Adobe H.264, QuickTime H.264 (via Adobe), QuickTime Pro, and Expression Encoder 4 Pro. Data rates are consistent among all encoders at GOP lengths greater than one. There is an anomoly with the Adobe H.264 codec compressing all-intra files.
The observed behavior occurs in all profiles, which were tested at Levels 4.1, 4.2, 5.0, and 5.1:
Image quality is better in the Adobe H.264 all-intraframe file, especially with respect to detail retention. The pictures below show sections of two consecutive frames magnified 400%. The file with N=2 is less accurate and contains noticeable blocking. Even the I-frames don't look as good in the files where N>1.
The test file was a seventeen second Premiere Pro sequence consisting of H.264, MPEG-2, and AE files with effects applied. Exports were rendered from the Premiere Pro timeline and from a V210 uncompressed 4:2:2 intermediate file of the sequence. The following settings were used:
Format: H.264
Width: 1280
Height: 720
Frame Rate: 24 fps
Field Order: Progressive
Aspect: Square Pixels (1.0)
TV Standard: NTSC
Profile: Baseline, Main, and High
Levels: 4.1, 4.2, 5.0, 5.1
Render at Maximum Bit Depth: Enabled
Bitrate Encoding: VBR, 2-Pass
Target Bitrate: Maximized for each Profile/Level
Maximum Bitrate: Maximized for each Profile/Level
Key Frame Distance: 1, 2, 3, 4, 5, 6, 7, 8, 12, 24, 48
Use Maximum Render Quality: Enabled
Multiplexer: MP4
Stream Capability: Standard
Software:
Adobe Media Encoder CS6 Creative Cloud v6.0.3.1 (64-bit)
Premiere Pro CS6 Creative Cloud v6.0.3
Windows 7 SP1
QuickTime Pro for Windows v7.6.9 (1680.9)
MediaInfo 0.7.62 (for GOP and data rate information)

I think the short answer is yes,
a h.264 encoder does I-frame only differently. I frames are complete expressions of a picture with no temporal compression information.
P frames use _P_redictive information. IE information from prior frames.
B frames use _B_i-directional predictive frame information.
h.264 gets the majority of it's bit saving from use of B and P frames. When you do I-frame only you only get the block compression and none of the advantages of P and B frames. Thus the GOP N=1 doesn't get very good bit's per pixel.
Having said all that I do find your comment...
Profitic wrote:
Note how the data rate drops 70% (from 2.17 to 0.66 bpp) even though 50% of the I-frames still exist when N=2. By comparison, here is the video data rate when exporting with QuickTime H.264:
... very interesting. Indeed, why is the datarate 70% less when it should at best be 50% for GOP N=2. 50% less should be the same I-frame information plus 0 bytes for the B frame between them. (GOP = I,B,I). Any more than that and it is throwing away bits from the I-frame. So, this seems to be to be a ratecontrol bug.
http://en.wikipedia.org/wiki/Group_of_pictures
"The GOP structure is often referred by two numbers, for example, M=3, N=12. The first number tells the distance between two anchor frames (I or P): it is the GOP size. The second one tells the distance between two full images (I-frames): it is the GOP length. For the example M=3, N=12, the GOP structure is IBBPBBPBBPBBI. Instead of the M parameter the maximal count of B-frames between two consecutive anchor frames can be used."

QT conversion and key frames

Hi,
I've been using very specific settings for awhile now to convert my short final cut movies to compressed movies for the web and all has been working well. I'm now doing this for a higher-end client and want all or most of the pixellation to go away.
Here are the settings I'm using for the video part:
Video settings:
MPEG4 Video
Frame rate: current
Key frames: every 15 frames
Compressor Quality: Best
Data Rate: Automatic
video size: 320x240
I'm just wondering if anyone has experience to know if I change the key frames to do every 5 or every 100--will that help my quality? Is there anything else I should be doing?
I've tried several tests, including using Compressor and doing h.264 streaming at 800kpbs and didn't see any difference in quality. (though I changed the video settings to reflect the above)
This is going on their website via YouTube so file size needs to be 1GB or less.
Thanks for your help!
DMB

Do some searching here (and googling) on video for youtube. Here's a good place to start:
http://www.kenstone.net/fcphomepage/you_tube_reduxgary.html

Why is the position of key frame BEFORE scene changes not after?

Why is the position of I frame BEFORE scene changes not after?
And, why doesn't MovieVideoChart show any I frames other than those that correspond to periodic "key frames every X frames"? Is it reading meta data and not really showing where the real existing I frames are located? I.e. WYSIAL (what you see is a lie)? If so, where can I get an affordable tool that will let me examine my files in this regard?
I have put compression and chapter marks at scene changes in FCP and have exported with markers for DVDSP (both chapter and compression).
I have read on this forum (somewhere) that when insert key frames every X frames is selected, Compressor is still going to insert key frames automatically at key frames.
When I last encoded with H.264 in Compressor, I selected option to insert I key frame every 90 frames (fps=29.97).
When I jump to chapter in my encoded video, where I had place a key frame at a cut, I end up with a chapter at the frame BEFORE the cut.
I will try moving my chapter/compression marks a frame ahead and see if that helps.
Certainly, others must have been plagued by this problem.
When encoding with MPEG2 for DVD, the same thing happens.
It is a real problem. I get one frame appearing before the cut in chapter skips.
Hope someone can illuminate this problem.

Hi there
As you have seen, RoboHelp doesn't understand how to create the layers you are wanting to achieve the effect in Word. It simply brings the images in as separate objects.
Basically there are two approaches you might consider.
You could insert Positioned Text Boxes and configure them to present the images as you want. If you take this approach, you will likely find yourself struggling to maintain the positioning consistently as well as noticing text flow issues. Personally, I'd avoid that approach.
The other approach involves displaying the images in your Word document so that you see them as intended, then screen capture so you grab the combined image. Then save that combined image and use it instead of the separate images in RoboHelp. This is the approach I'd suggest and that I use myself.
Cheers... Rick
Helpful and Handy Links
RoboHelp Wish Form/Bug Reporting Form
Begin learning RoboHelp HTML 7, 8 or 9 within the day!
Adobe Certified RoboHelp HTML Training
SorcerStone Blog
RoboHelp eBooks

PGC...data rate too high

Hallo,
message
nunew33, "Mpeg not valid error message" #4, 31 Jan 2006 3:29 pm describes a certain error message. The user had problems with an imported MPEG movie.
Now I receive the same message, but the MPEG that is causing the problem is created by Encore DVD itself!?
I am working with the german version, but here is a rough translation of the message:
"PGC 'Weitere Bilder' has an error at 00:36:42:07.
The data rate of this file is too high for DVD. You must replace the file with one of a lower data rate. - PGC Info: Name = Weitere Bilder, Ref = SApgc, Time = 00:36:42:07"
My test project has two menus and a slide show with approx. 25 slides and blending as transition. The menus are ok, I verified that before.
First I thought it was a problem with the audio I use in the slide show. Because I am still in the state of learning how to use the application, I use some test data. The audio tracks are MP3s. I learned already that it is better to convert the MP3s to WAV files with certain properties.
I did that, but still the DVD generation was not successful.
Then I deleted all slides from the slide show but the first. Now the generation worked!? As far as a single slide (an image file) can not have a bitrate per second, and there was no sound any more, and as far as the error message appears AFTER the slide shows are generated, while Encore DVD is importing video and audio just before the burning process, I think that the MPEG that is showing the slide show is the problem.
But this MPEG is created by Encore DVD itself. Can Encore DVD create Data that is not compliant to the DVD specs?
The last two days I had to find out the cause for a "general error". Eventually I found out that image names must not be too long. Now there is something else, and I still have to just waste time for finding solutions for apparent bugs in Encore DVD. Why doesn't the project check find and tell me such problems? Problem is that the errors appear at the end of the generation process, so I always have to wait for - in my case - approx. 30 minutes.
If the project check would have told me before that there are files with file names that are too long, I wouldn't have had to search or this for two days.
Now I get this PGC error (what is PGC by the way?), and still have no clue, cause again the project check didn't mention anything.
Any help would be greatly appreciated.
Regards,
Christian Kirchhoff

Hallo,
thanks, Ruud and Jeff, for your comments.
The images are all scans of ancient paintings. And they are all rather dark. They are not "optimized", meaning they are JPGs right now (RGB), and they are bigger then the resolution for PAL 3:4 would require. I just found out that if I choose "None" as scaling, there is no error, and the generation of the DVD is much, much faster.
A DVD with a slide show containing two slides and a 4 second transition takes about 3 minutes to generate when the scaling is set to something other than "None". Without scaling it takes approx. 14 seconds. The resulting movies size is the same (5,35 MB).
I wonder why the time differs so much. Obviously the images have to be scaled to the target size. But it seems that the images are not scaled only once, that those scaled versions of the source images are cached, and those cached versions are used to generate then blend effect, but for every frame the source images seem to be scaled again.
So I presume that the scaling - unfortunately - has an effect on the resulting movie, too, and thus influences the success of the process of DVD generation.
basic situation:
good image > 4 secs blend > bad image => error
variations:
other blend times don't cause an error:
good image > 2 secs blend > bad image => success
good image > 8 secs blend > bad image => success
other transitions cause an error, too:
good image > 4 secs fade to black > bad image => error
good image > 4 secs page turn > bad image => error
changing the image order prevents the error:
bad image > 4 secs blend > good image => success
changing the format of the bad image to TIFF doesn't prevent the error.
changing colors/brightness of the bad image: a drastic change prevents the error. I adjusted the histogram and made everything much lighter.
Just a gamma correction with values between 1.2 and 2.0 didn't help.
changing the image size prevents the error. I decreased the size. The resulting image was still bigger than the monitor area, thus it still had to be scaled a bit by Encore DVD, but with this smaller version the error didn't occur. The original image is approx. 2000 px x 1400 px. Decreasing the size by 50% helped. Less scaling (I tried 90%, 80%, 70% and 60%, too) didn't help.
using a slightly blurred version (gaussian blur, 2 px, in Photoshop CS) of the bad image prevents the error.
My guess is that the error depends on rather subtle image properties. The blur doesn't change the images average brightness, the balance of colors or the size of the image, but still the error was gone afterwards.
The problem is that I will work with slide shows that contain more images than two. It would be too time consuming to try to generate the DVD over and over again, look at which slide an error occurs, change that slide, and then generate again. Even the testing I am doing right now already "ate" a couple of days of my working time.
Only thing I can do is to use a two image slide show and test image couple after image couple. If n is the number of images, I will spend (n - 1) times 3 minutes (which is the average time to create a two slides slide how with a blend). But of course I will try to prepare the images and make them as big as the monitor resolution, so Encore DVD doesn't have to scale the images any more. That'll make the whole generation process much shorter.
If I use JPGs or TIFFs, the pixel aspect ratio is not preserved when the image is imported. I scaled one of the images in Photoshop, using a modified menu file that was installed with Encore DVD, because it already has the correct size for PAL, the pixel aspect ratio and the guides for the save areas. I saved the image as TIFF and as PSD and imported both into Encore DVD. The TIFF is rendered with a 1:1 pixel aspect ratio and NOT with the D1/DV PAL aspect ration that is stored in the TIFF. Thus the image gets narrowed and isn't displayed the way I wanted it any more. Only the PSD looks correct. But I think I saw this already in another thread...
I cannot really understand why the MPEG encoding engine would produce bit rates that are illegal and that are not accepted afterwards, when Encore DVD is putting together all the stuff. Why is the MPEG encoding engine itself not throwing an error during the encoding process? This would save the developer so much time. Instead they have to wait until the end, thinking everything went right, and find out then that there was a problem.
Still, if sometime somebody finds out more about the whole matter I would be glad about further explanations.
Best regards,
Christian

Importance of Key Frame Interval in live streaming

What is the significance of Key frame interval in live streaming. In VOD I know that media players seeks between these keyframes but what is use of it in live streaming. Any effect on quality ?
Please help
-Prem

Sorry the recommendations didn't work. I tested two 1080p files – one 23.98 fps and a 29.97 fps – at those settings. No loss of sync whatsoever here.
So perhaps there is something about your source file that's a problem. Try another file and see.
On a different, but related topic, the MPEG4 encoding that Compressor 3.5 uses is kind of long in the tooth. You'll note in the user manual that all the discussion about features and settings seems to presume that the file will not be re-encoded. (Hence, my question about whether it was for your own Web Site.)
All the video services take whatever we upload and re-encode them to their proprietary specs. So generally it's best to upload as much info as possible. (David Brewer, who frequently contributes to these boards, uploads very large Pro Res files with good results.)
YT's advanced encoding guidelines recommend the MP4 container, but with the h.264 codec. That is the Part 10 MPEG standard, which Compressor 3.0 and 3.5 cannot do. (However, Compressor 4.0 can do that encode, which is one of benefits of having that version.)
FWIW, all videos that I prepare for the Web are h.264 .mov files (not mp4) and I've not had any quality issues with video or audio. Just personal preference.
Perhaps someone else will have some ideas why you lose sync other than sample rate and/or change in frame rate.
Good luck.
Russ

YouTube - Key Frames, Data Rate, Encoding

Similar Messages

Maybe you are looking for