| Author |
Message |
NerdWithNoLife
Member
Joined: 27 Mar 2008
Location: United States
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| hotforwords wrote: |
I've got a new one for you. As of the most recent YouTube maintenance upgrade... I cannot get my thumbnails to line up correctly.
Let me explain. YouTube allows you to pick one of 3 thumbnails from 25%, 50% and 75% .. now I do a frame count and calculate the thumbs that way.. to make sure I don't have a funny look in the thumbnail - and it's been 100% accurate.
Now I cannot get them to line up.. I am around 3-7 frames off. And I have to do a trial and error now for each new video.
Can any of you figure out why the frames no longer line up? Is YouTube adding some randomness into their algorithm? Or have they departed from the 30fps.. and maybe it's now 29.97?? Or is the final product something else? |
I didn't see a reply to this issue so... YouTube seems happy with 29.97 frames per second to me, I'm not sure why others recommend a clean 30. It is possible that the flash container prefers 30, but it hasn't been an issue with me.
Anyway, US cameras generally shoot 29.97 and 23.976 frames per second, not truly 30 and 24. If you convert your video to 30, you're speeding the frame rates up slightly so every thousand frames one is repeated. This means you're a frame off every 33 and 1/3 seconds. So by the end of a 3 minute video you'd be 5 frames off. If you need to convert, go by your original 29.97 rate and multiply the desired frame by 1001, then divide by 1000.
Let's say frame 2700 is your center image. So 2700 x 1001 / 1000 = 2702.7. Thus the desired center frame would actually be frame 2703 in the converted 30fps video. Or do it the other way around (frame x 1000 / 1001) if you're doing the reverse.
And you can blame this complication on the jerry-rigged switch from black and white to color TV 50 years ago.
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Duc851
Member
Joined: 20 Jan 2003
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Well here's something I found out by accident. I'm a musician and I made a video using NeroVision to export with a 720x480 Mpeg-2 video and 24/96 wav audio in the project.
Exported that to Nero Digital AVC at 320x240 and 2 pass vbr. The only option for audio is stereo or 5.1 so I choose stereo which matches my Wav source file.
What I ended up with was a very small size mp4 file using a HE-AAC audio stream.
Here's what I like about it with my slow DSL connection.
I can type in &fmt=18 and the video plays back in high quality audio with no buffering hesitation.
I tried the 640x480 method with high bitrate and I do see the option selections on the video but high quality playback stalls on my connection.
So if you are like me and don't care as much about video quality and only want audio quality to share with a wider audience this may be a way. Here's my video in the high quality mode:
http://www.youtube.com/watch?v=mdH1vhxkvL0&fmt=18
Funny thing is that once I load the video using the &fmt=18 trick I then see the choice to view in standard quality.
The choice is not there without the &fmt=18 in the URL.
Anyone know how to make the &fmt=18 video the default?
It's great for me because people with slow connections can enjoy the superior audio seamlessly!
Gil
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ricardouk
Member
Joined: 15 Mar 2005
Location: PORTUGAL
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I think you got something here Duc851.
i can confirm that theres no buffering/pause once i load the video, i only see that happening with standart quality (flv <350), all the "fmt" high quality links posted here pause lots of times on my 512k connection, this is the first "high quality" video that i manage to see without pausing.
Are they doing tests on replacing flv with mp4 for standart quality? hope so
General #0
Format : MPEG-4
Format/Info : ISO 14496-1 version 2
Format/Family : MPEG-4
File size : 8.82 MiB
PlayTime : 3mn 47s
Bit rate : 325 Kbps
StreamSize : 70.3 KiB
Video #0
Codec : AVC
Codec/Family : AVC
Codec/Info : H.264 (3GPP)
PlayTime : 3mn 47s
Bit rate : 214 Kbps
Width : 320 pixels
Height : 240 pixels
Display Aspect ratio : 4/3
Frame rate : 29.970 fps
Bits/(Pixel*Frame) : 0.093
StreamSize : 5.80 MiB
Audio #0
Codec : AAC LC
Codec/Family : AAC
Codec/Info : AAC Low Complexity
PlayTime : 3mn 47s
Bit rate mode : VBR
Bit rate : 109 Kbps
Channel(s) : 2 channels
Channel positions : L R
Sampling rate : 44.1 KHz
Resolution : 16 bits
_________________
I love it when a plan comes together!
Ricardo Santos
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legendhouse
Member
Joined: 31 Mar 2008
Location: United States
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| NerdWithNoLife wrote: |
| hotforwords wrote: |
I've got a new one for you. As of the most recent YouTube maintenance upgrade... I cannot get my thumbnails to line up correctly.
Let me explain. YouTube allows you to pick one of 3 thumbnails from 25%, 50% and 75% .. now I do a frame count and calculate the thumbs that way.. to make sure I don't have a funny look in the thumbnail - and it's been 100% accurate.
Now I cannot get them to line up.. I am around 3-7 frames off. And I have to do a trial and error now for each new video.
Can any of you figure out why the frames no longer line up? Is YouTube adding some randomness into their algorithm? Or have they departed from the 30fps.. and maybe it's now 29.97?? Or is the final product something else? |
I didn't see a reply to this issue so... YouTube seems happy with 29.97 frames per second to me, I'm not sure why others recommend a clean 30. It is possible that the flash container prefers 30, but it hasn't been an issue with me.
Anyway, US cameras generally shoot 29.97 and 23.976 frames per second, not truly 30 and 24. If you convert your video to 30, you're speeding the frame rates up slightly so every thousand frames one is repeated. This means you're a frame off every 33 and 1/3 seconds. So by the end of a 3 minute video you'd be 5 frames off. If you need to convert, go by your original 29.97 rate and multiply the desired frame by 1001, then divide by 1000.
Let's say frame 2700 is your center image. So 2700 x 1001 / 1000 = 2702.7. Thus the desired center frame would actually be frame 2703 in the converted 30fps video. Or do it the other way around (frame x 1000 / 1001) if you're doing the reverse.
And you can blame this complication on the jerry-rigged switch from black and white to color TV 50 years ago. |
I noticed that with Sony Vegas I can't get it right anymore either.I do the trial and error too.
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ricardouk
Member
Joined: 15 Mar 2005
Location: PORTUGAL
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I reuploaded Duc's mp4, hope he doesnt mind, to see if youtube reencodes the mp4, added the fmt18 bit and it was available straight away.
http://www.youtube.com/watch?v=Gx_j8n0IiPo&fmt=18
Does this mean we are nearer to find the optimal mp4 settings like we did for flv without reencoding?
edit: it seems the fmt version is the flv version. 
_________________
I love it when a plan comes together!
Ricardo Santos
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Duc851
Member
Joined: 20 Jan 2003
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Don't mind at all!
After all it's for science.
I think I may have accidentally stumbled upon a method to provide 320x240 video with the capability of high quality stereo audio which for me as a musician is ideal!
The only annoying thing is I have to manually put in the &fmt=18 bit at the end to get the choices to show up.
Let's find a way to get the video uploaded that goes to the format 18 video by default if we can.
Otherwise I'm considering just disabling video comments and posting a notice about what to do to hear the higher quality instead.
The setting I used to encode in Nerovision was the "Nero Digital" profile which encodes AVC (H.264) video using HE-AAC which in my opinion sound better than AAC. YouTube probably converts that stream back to regular AAC I'd imagine?
Thanks also for posting the video data, very helpful!
Cheers, Gil
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NerdWithNoLife
Member
Joined: 27 Mar 2008
Location: United States
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| ricardouk wrote: |
| edit: it seems the fmt version is the flv version. |
Which could be evidence that they will reencode EVERYTHING, no matter how well it adheres to the standards. I've been trying this for a couple weeks, and everything has been reencoded so far. Hopefully there is a way, or else I'll continue doing < 350k flash files. I mean I have it so close to their specs the only difference is there isn't a (C) 2007 Google Inc. v06.24.2007. in the title and still nothing.
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Duc851
Member
Joined: 20 Jan 2003
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| ricardouk wrote: |
I reuploaded Duc's mp4, hope he doesnt mind, to see if youtube reencodes the mp4, added the fmt18 bit and it was available straight away.
http://www.youtube.com/watch?v=Gx_j8n0IiPo&fmt=18
Does this mean we are nearer to find the optimal mp4 settings like we did for flv without reencoding?
edit: it seems the fmt version is the flv version. |
Interesting, I went and listened on your channel and noticed a degradation in sound quality in the louder places.
I guess that has to do with YouTube reconverting?
Right now I am converting my high quality MPEG-2 (720x480 progressive 2 pass VBR with full LPCM audio @ 1536 kbps) using AnyVideoConverter and encoding with the x264 codec to 320x240 with 325 video bit rate + 25 fps and AAC 192kbps 44.1 Khz audio. If successful I will post it.
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ricardouk
Member
Joined: 15 Mar 2005
Location: PORTUGAL
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I noticed you uploaded the video today, so it didnt take for the mp4 version to be available, that is good, will it be available globally that fast for everyone or only certain countries?
| Duc851 wrote: |
Exported that to Nero Digital AVC at 320x240 and 2 pass vbr. The only option for audio is stereo or 5.1 so I choose stereo which matches my Wav source file.
What I ended up with was a very small size mp4 file using a HE-AAC audio stream.
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will try to replicate your settings with AutoMKv, and upload a sample to see if it works.
| Duc851 wrote: |
Here's what I like about it with my slow DSL connection.
I can type in &fmt=18 and the video plays back in high quality audio with no buffering hesitation.
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yes that is the "bit" that i'm interested aswell. At the same video bitrate, resolution, andaudio rate avc is supposed to have more quality than flv <350
if i could get that even if i have to wait for reencoding it would be a nice start.
| Duc851 wrote: |
Interesting, I went and listened on your channel and noticed a degradation in sound quality in the louder places.
I guess that has to do with YouTube reconverting?
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yes that's what i think
_________________
I love it when a plan comes together!
Ricardo Santos
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ricardouk
Member
Joined: 15 Mar 2005
Location: PORTUGAL
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it seems the fmt version is now "live", after one hour more or less, internet download manager just picked it up now, by the size it looks like it was reconverted....will compare both, but i think NerdWithNoLife is right and its reconverting everything.
_________________
I love it when a plan comes together!
Ricardo Santos
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NerdWithNoLife
Member
Joined: 27 Mar 2008
Location: United States
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I would recommend 128k vbr AAC audio if you're doing this. Most fmt=18's I've found use that setting, though the actual bitrate often ends up lower (92, 108, etc..). But I believe 128k is the target bitrate (that's what AviDemux reports).
And the video bitrate on this latest video is 214, which could simply be the result of a smaller screen size and lower bitrate in the original file. Even my flv's get changed to fmt=18 eventually though, with 128k vbr AAC (just a rehash though).
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ricardouk
Member
Joined: 15 Mar 2005
Location: PORTUGAL
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heres the comparison between Duc's downloaded mp4 file, and in red after i reuploaded the same mp4, it didnt touch the audio
General #0
Format : MPEG-4
Format/Info : ISO 14496-1 version 2
Format/Family : MPEG-4
File size : 8.82 MiB --------->: 8.34 MiB
PlayTime : 3mn 47s
Bit rate : 325 Kbps --------->: 307 Kbps
StreamSize : 70.3 KiB
Video #0
Codec : AVC
Codec/Family : AVC
Codec/Info : H.264 (3GPP)
PlayTime : 3mn 47s
Bit rate : 214 Kbps --------->: 196 Kbps
Width : 320 pixels
Height : 240 pixels
Display Aspect ratio : 4/3
Frame rate : 29.970 fps
Bits/(Pixel*Frame) : 0.093 --------->: 0.085
StreamSize : 5.80 MiB --------->: 5.31 MiB
Audio #0
Codec : AAC LC
Codec/Family : AAC
Codec/Info : AAC Low Complexity
PlayTime : 3mn 47s
Bit rate mode : VBR
Bit rate : 109 Kbps
Channel(s) : 2 channels
Channel positions : L R
Sampling rate : 44.1 KHz
Resolution : 16 bits
StreamSize : 2.96 MiB
_________________
I love it when a plan comes together!
Ricardo Santos
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Duc851
Member
Joined: 20 Jan 2003
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| NerdWithNoLife wrote: |
I would recommend 128k vbr AAC audio if you're doing this. Most fmt=18's I've found use that setting, though the actual bitrate often ends up lower (92, 108, etc..). But I believe 128k is the target bitrate (that's what AviDemux reports).
And the video bitrate on this latest video is 214, which could simply be the result of a smaller screen size and lower bitrate in the original file. Even my flv's get changed to fmt=18 eventually though, with 128k vbr AAC (just a rehash though). |
Interesting to note that I was uploading FLVs using the correct settings in AnyVideoConverter and it actually preserved my stereo sound of the original. I have an flv uploaded that I tried the fmt=18 on and I have to tell you that the sound quality ws inferior in this case. Sounded slightly distorted in fmt=18 mode.
I think the answer is mp4 AAC for audio although I had HE-AAC on the original which was probably reconverted to AAC by YouTube.
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Duc851
Member
Joined: 20 Jan 2003
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k.
Member
Joined: 11 Mar 2008
Location: United States
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Last edited by k. on May 23, 2008 04:24, edited 1 time in total
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Duc851
Member
Joined: 20 Jan 2003
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Spoke too soon fmt=18 comes up now with high quality stereo audio and actually sounds better than the original HE-AAC mp4 I uploaded. Perhaps using the full 192 kbps worked better (I know YouTube reconverts this so it is lower but at least I put quality in hoping it made some difference)
http://www.youtube.com/watch?v=YKJruFON6UY&fmt=18
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ricardouk
Member
Joined: 15 Mar 2005
Location: PORTUGAL
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another test, fmt18 was live after 15/20m
General #0
Format : MPEG-4
Format/Info : ISO 14496-1 Base Media---------->: ISO 14496-1 version 2
Format/Family : MPEG-4
File size : 2.43 MiB
PlayTime : 1mn 1s
Bit rate : 333 Kbps------>: 323 Kbps
StreamSize : 28.3 KiB------>: 18.7 KiB
Video #0
Codec : AVC
Codec/Family : AVC
Codec/Info : H.264 (3GPP)
PlayTime : 1mn 1s
Bit rate : 214 Kbps---------->: 197 Kbps
Width : 320 pixels
Height : 240 pixels
Display Aspect ratio : 4/3
Frame rate : 25.000 fps-------->: 24.984 fps
Bits/(Pixel*Frame) : 0.112--------->: 0.103
StreamSize : 1.56 MiB
Audio #0
Codec : AAC LC
Codec/Family : AAC
Codec/Info : AAC Low Complexity
PlayTime : 1mn 1s
Bit rate mode : VBR
Bit rate : 115 Kbps--------->: 125 Kbps
Channel(s) : 2 channels
Channel positions : L R
Sampling rate : 44.1 KHz
Resolution : 16 bits
StreamSize : 861 KiB----------->: 936 KiB
_________________
I love it when a plan comes together!
Ricardo Santos
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Duc851
Member
Joined: 20 Jan 2003
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Is that a test video of your own?
I've decided to disable video comments after posting a comment for people alerting them how to force the High Quality Audio version. It's more importatnt to me that people hear the high quality version than getting comments.
Wish I could make it default to the fmt=18 version.
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NerdWithNoLife
Member
Joined: 27 Mar 2008
Location: United States
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BTW, I found a way to create a file in the Version 2 format, not Base Media. Drag the clips into Yamb making sure that one video (H264) and one audio (AAC) track is checked. Click on properties and in the Brand Name dropdown select Iso Media File. Then create the mp4 and it will be ISO 14496-1 Version 2, just the way we like it.
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Denizzje
Member
Joined: 16 Feb 2008
Location: Netherlands
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And what is the difference between version 2 and base media?
_________________
Touchy sensitive dude  .
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NerdWithNoLife
Member
Joined: 27 Mar 2008
Location: United States
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It's a container/labeling issue, I think. The video/audio should stay the same, it just gives the decoding program more information. It gets complicated, but here is a discussion: http://forum.doom9.org/showthread.php?t=135127. Some suggest that base media technically doesn't conform to the standards of the decoding software that is out there (I think that's what they're saying?). Not my area of expertise but I do know that all the mp4's I've gotten back from YouTube are in the ISO 14496-1 Version 2 format.
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NerdWithNoLife
Member
Joined: 27 Mar 2008
Location: United States
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This is what I mean. Here's a comparison between what I gave and what I got:
| Code: |
General #0 Original What Came Back
Complete name : C:\Documents and Set... | C:\Documents and Set...
Format : MPEG-4 | MPEG-4
Format/Info : ISO 14496-1 version 2 | ISO 14496-1 version 2
Format/Family : MPEG-4 | MPEG-4
File size : 1.05 MiB | 817 KiB
PlayTime : 20s 61ms | 15s 696ms
Bit rate : 441 Kbps | 426 Kbps
StreamSize : 6.79 KiB | 5.91 KiB
Encoded date : UTC 2008-05-02 00:27:03 | UTC 2008-05-02 00:34:26
Tagged date : UTC 2008-05-02 00:27:03 | UTC 2008-05-02 00:34:26
Video #0
Codec : H.264 | H.264
Codec/Info : H.264 (3GPP) | H.264 (3GPP)
PlayTime : 15s 248ms | 15s 181ms
Bit rate : 412 Kbps | 302 Kbps
Width : 480 pixels | 480 pixels
Height : 360 pixels | 360 pixels
Aspect ratio : 4/3 | 4/3
Frame rate : 29.970 fps | 29.970 fps
Bits/(Pixel*Frame) : 0.059 | 0.055
StreamSize : 766 KiB | 559 KiB
Title : | (C) 2007 Google Inc. v06.24.2007.
Encoded date : UTC 2008-05-02 00:27:03 | UTC 2008-05-02 00:34:26
Tagged date : UTC 2008-05-02 00:27:03 | UTC 2008-05-02 00:34:26
Audio #0
Codec : AAC LC | AAC LC
Codec/Info : AAC Low Complexity | AAC Low Complexity
PlayTime : 20s 62ms | 15s 696ms
Bit rate : 125 Kbps | 131 Kbps
Bit rate mode : VBR | VBR
Channel(s) : 2 channels | 2 channels
Sampling rate : 44 KHz | 44 KHz
Resolution : 16 bits | 16 bits
StreamSize : 306 KiB | 251 KiB
Title : | (C) 2007 Google Inc. v06.24.2007.
Encoded date : UTC 2008-05-02 00:27:03 | UTC 2008-05-02 00:34:26
Tagged date : UTC 2008-05-02 00:27:03 | UTC 2008-05-02 00:34:26 |
Is it too much to ask to do a nice encode myself without YouTube meddling with it? Although now that I look at it, perhaps the audio is too long and triggered the reencode because it was created separately, then muxed together with YAMB. But maybe not. This is getting to the point of madness...
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ricardouk
Member
Joined: 15 Mar 2005
Location: PORTUGAL
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| NerdWithNoLife wrote: |
| This is getting to the point of madness... |
I agree, i've stoped and will carry on doing the <350 flv hack.
im using www.blip.tv to store the higher quality mp4 videos, it doesnt recovert them and i can use the video permalink to use a different player.
I guess we will have to wait untill that happens with youtube or any other video site.
_________________
I love it when a plan comes together!
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