Prepare media for HLS ABR streaming multilanguage VOD?
 

Hi all,
i'm new on this forum and i'm new also about video and streaming. :eek:

I'm studying about video formats and procedures to encode a video to H.264 (MP4) for HLS Adaptive Bitrate providing also multi language audio contents.

I Use CDN storage with HLS NGNIX server technology to stream video content from m3u8 manifest and a player HTML5 like most popular jwplayer..videojs... ecc. to publish content on web pages.

The file i do (or i need to do in a simpler manner) is MPEG-4 (H.264 25fps / AAC 48Khz 320kbps) with multiple audio tracks... also prepared in different resolutions and weights for ABR.

So I have some problems when i have to prepare files with multi-language audio content due to too many steps i have to do and i think in those many steps of corrupt something in the video.

Indeed in the stream something goes wrong, the video drop during playback in many players, changing language and rez in the player cause video crash.

The CDN stream support told me, based on NGINX logs... , something that i don't really understand:

"From what the admin found it appears that the video files have different GOP size/Iframes/Bframes which is what causes the player to have trouble with the playback. According to him the ideal GOP length to set would be 2x the frame rate and for the key Frame to have it set a 1x the frame rate. Also he said to not use bf frames if your using them"


These are the steps i do.

I Start from Adobe Premiere to make video 1080p with multi audio tracks and here i have the first problem that file result with 2 Stereo audio tracks with the same name, English / English ( I need to have English / Italian / Swedish ecc..).

I use Handbrake to compressed video to H.264 (MP4), i change in Video only Framerate FPS to same as source and Average Bitrate to 5000 to make first compression and Audio i put 2 English tracks to AAC 320kbps. stop


After i use mp4tools to change label of second audio language track to "Sweden" creating a new file Audio and Video Pass Thru.

After that i create 1080,720,480,360.... rez with mp4tools.

I can't use any other software because adobe media encoder, compress and other software remove the second audio track during creation of mp4.

Any suggestion about simplify these processes or am i wrong all ? Someone have understood what CDN Admin are saying ?
I looked for that parameters bframes lframes etc.. i found only in handbrake something in advanced section that seems marked as deprecated.

Thanks in advance,
Mariano

Are you multi-casting multiple video sizes, and automatically switching between streams based on user bandwidth availability? I'm not entirely positive that the tech/admin isn't spouting nonsense, but equal GOP length for all streams does make sense in that setting.

Handbrake "does stuff" in the background because it treats users like morons. It's software for newbies, and shields them from a lot of things. But you probably need more control over the final output. A better approach would to be something like Hybrid, which gives very granular control over every aspect of the encore. Of all the GUIs, Hybrid is not far off from the command line interface.

There are tools to remux MP4, so not need to recompress with Handbrake at all ... if I'm reading that correctly.

I wish the net would adopt MKV more than MP4. It's open and free, and much better to work with. I just looked, and it's on the HLS nginx roadmap. That's something, I guess, but does nothing for you right now.