Stream capture from NBCOlympics

[nwtim]

I grabbed 10 audio fragment files and renamed them to 1,2,3,etc and was able to "join" them with AdobeHDS.php. It still created a file named Joined.flv, but I wasn't able to hear anything despite VLC being able to "play" it.

MediaInfo says this about it:

General
Complete name : E:\My Documents\Downloads\dTa\Test\Joined_101-110_Audio.flv
Format : Flash Video
File size : 423 KiB
Duration : 59s 954ms
Overall bit rate : 57.8 Kbps

Audio
Format : AAC
Format/Info : Advanced Audio Codec
Format profile : HE-AAC / LC
Codec ID : 10
Duration : 59s 954ms
Channel(s) : 2 channels
Channel positions : Front: L R
Sampling rate : 44.1 KHz / 22.05 KHz
Compression mode : Lossy

I joined the 10 video fragments that should match the audio fragments and MediaInfo reports:

General
Complete name : E:\My Documents\Downloads\dTa\Test\Joined_101-110_Video.flv
Format : Flash Video
File size : 24.7 MiB
Duration : 1mn 0s
Overall bit rate mode : Constant
Overall bit rate : 3 454 Kbps

Video
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L3.1
Format settings, CABAC : Yes
Format settings, ReFrames : 4 frames
Codec ID : 7
Duration : 1mn 0s
Bit rate mode : Constant
Bit rate : 3 450 Kbps
Width : 1 280 pixels
Height : 720 pixels
Display aspect ratio : 16:9
Frame rate mode : Constant
Frame rate : 25.000 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.150
Stream size : 23.7 MiB (96%)

I see there's a small difference in the duration of the files, so muxing them - if it's even possible - would likely end in a slight offset - and that may very well be where the keyframes come in.

I'm not really sure where to go from here other than seeing if there's some way to mux them together.

[nwtim]

I just realized that the fragments I had tested with were from a commercial break. Trying a different portion now...

[nwtim]

Okay, I joined the audio and video of a completely different range of fragments and am getting audio from the joined audio files and video from the joined video files. If I play the video in one player and the audio in another, it actually sounds and looks like a great video. So now to see if I can join them - I'm not sure how flash video and audio works for muxing (as opposed to mpa and mpv files).

[nwtim]

Okay, I got the audio and video to mux together using Video-to-Video Converter (http://www.videohelp.com/tools/Video...deo-Converter), but the synchronization is way off (the audio for fragment 770 was not even close to the video of fragment 770). I'm going to have to look into it when I have more time.

Give it a shot and share any ideas you come up with.

Edit:
I think the audio synchronization was my fault. I noticed that the audio leads the video by about 5-6 seconds throughout a 2-hour recording, so I'm guessing when I renumbered the files I missed an audio fragment at the beginning. I'm going to give it another go.

[ehurdler]

I am kind of at the same stage now as you are. I got great video, and great audio....Just unfortunately the sync time was over an hour off. So I am deleting some 728 fragments of video and re-joining. This will have the same number of audio and video fragments. Maybe it will match. If not, I think I have by having videio open in vlc and audio opened in iTunes the difference in time. May have to fiddle with delays and seconds to chop out, but I may be close. I am using a mac and have MKV Tools to mux the tracks together. That is of course after I run both thru a different program to get .acc audio, and .mkv video.

I will let you know my progress as well. I am hopeful that I am close enough to get it working with minor tweaks now.

[chap]

try simple

ffmpeg -i "http://olystreameast.nbcolympics.com/vod/8ea27d49-ddab-48cd-8d4e-89eecd346124/ladies--short-program0219054304.ism/QualityLevels(56000)/Manifest(audio_en_0,format=m3u8-aapl,filtername=vodcut)" -i "http://olystreameast.nbcolympics.com/vod/8ea27d49-ddab-48cd-8d4e-89eecd346124/ladies--short-program0219054304.ism/QualityLevels(3450000)/Manifest(video,format=m3u8-aapl,filtername=vodcut)" -c copy t.ts

[nwtim]

Originally Posted by chap

try simple

ffmpeg -i "http://olystreameast.nbcolympics.com/vod/8ea27d49-ddab-48cd-8d4e-89eecd346124/ladies--short-program0219054304.ism/QualityLevels(56000)/Manifest(audio_en_0,format=m3u8-aapl,filtername=vodcut)" -i "http://olystreameast.nbcolympics.com/vod/8ea27d49-ddab-48cd-8d4e-89eecd346124/ladies--short-program0219054304.ism/QualityLevels(3450000)/Manifest(video,format=m3u8-aapl,filtername=vodcut)" -c copy t.ts

Whoa! - That worked!!! (at least for the first 26 minutes of video - see below) That's exactly the way I was getting all my events from the London Olympics, but in all the dozens of links I examined, I never once saw an m3u8 one!

Did you actually find that link for the audio and m3u8 - or did you configure it based on the link I provided?

After the first 26 minutes, ffmpeg reported the error:

Invalid timestamps stream=0, pts=8786, dts=8589928978, size=67389
[mpegts @ 0731c800] Application provided invalid, non monotonically increasing d
ts to muxer in stream 0: 141188399 >= -8448742593
av_interleaved_write_frame(): Invalid argument

I do have an outdated ffmpeg, so I don't know if that was the cause, but still I'm pretty amazed that you found that link.

[nwtim]

Originally Posted by ehurdler

I am kind of at the same stage now as you are. I got great video, and great audio....Just unfortunately the sync time was over an hour off. So I am deleting some 728 fragments of video and re-joining. This will have the same number of audio and video fragments. Maybe it will match. If not, I think I have by having videio open in vlc and audio opened in iTunes the difference in time. May have to fiddle with delays and seconds to chop out, but I may be close. I am using a mac and have MKV Tools to mux the tracks together. That is of course after I run both thru a different program to get .acc audio, and .mkv video.

I will let you know my progress as well. I am hopeful that I am close enough to get it working with minor tweaks now.

I re-ran the mux with one more audio fragment at the front and the synchronization seemed perfect all the way through the 2+ hours I did. The trick was to make sure I streamed the video from NBCOlympics and noted the first fragment number reported by Web Console. In the case of the video I grabbed and muxed, the web stream started at fragment 715, so I renamed the video fragment "...Seg1-Frag715" to "1" and the audio fragment "...Seg1-Frag714" to "1".

I'd sure like to know where "chap" came up with the m3u8 link, because that's by far the easiest method (as long as I can get past the error I mentioned above).

[nwtim]

Originally Posted by chap

try simple

ffmpeg -i "http://olystreameast.nbcolympics.com/vod/8ea27d49-ddab-48cd-8d4e-89eecd346124/ladies--short-program0219054304.ism/QualityLevels(56000)/Manifest(audio_en_0,format=m3u8-aapl,filtername=vodcut)" -i "http://olystreameast.nbcolympics.com/vod/8ea27d49-ddab-48cd-8d4e-89eecd346124/ladies--short-program0219054304.ism/QualityLevels(3450000)/Manifest(video,format=m3u8-aapl,filtername=vodcut)" -c copy t.ts

Okay, I think I see what you did, but I have no idea how you knew the syntax.

It looks like you took the manifest string I provided up to the ".ism/manifest" and replaced "manifest" with "QualityLevels(56000)/Manifest(audio_en_0,format=m3u8-aapl,filtername=vodcut)" for the audio and then send another -i argument with the same string but this time replacing "manifest" with
"QualityLevels(3450000)/Manifest(video,format=m3u8-aapl,filtername=vodcut)" for the video.

That's brilliant, but how did you know to try this? Is this simply using ffmpeg to construct the .ts video out of the manifest link?

[nwtim]

Although using ffmpeg is a brilliant solution when programs can be grabbed without error, I've had no luck getting complete programs on 2 of the 4 programs I've tried it with - notably the women's gold medal hockey game and the ladies figure skating short program. Also, my trusty old workarounds, the -ss and -t switch, don't seem to work at all with this way of using ffmpeg.

I've found that using DownloadThemAll in conjuction with AdobeHDS.php I can get pretty good sized chunks of a program and join and mux the good segments with a perfect result, but I'm having a heckuva time trying to identify the problem fragments that consistently cause AdobeHDS.php to abort with a "Unknown packet type 58 (sometimes 54) encountered! Unable to proceed." error.

I would really appreciate any thoughts or ideas anyone has on this.