CODECS options in a m3u8 File??

[aj-stream]

Hello,
Where can I get a list of the options/flags that go in the CODECS line of a m3u8 file?

For example; in this Apple.com page, it lists the CODECS line.

#EXT-X-STREAM-INF:BANDWIDTH=150000,RESOLUTION=416x234,CODECS="avc1.42e00a,mp4a.40.2"
http://example.com/low/index.m3u8

Yet, where can I get a list of those options?


I am using ffmpeg -i myFile.ts
to find out the properties of my file.
How can I turn those properties in what is needed by the CODECS line?

[jagabo]

Open the m3u8 file in a text editor.

[aj-stream]

Open the m3u8 file in a text editor.

Yeah.
I am creating the m3u8 file.

What I need to know is what goes in the CODECS section.

[jagabo]

So you're looking for a list of possible values, not the value for a particular video? Maybe here:

https://wiki.whatwg.org/wiki/video_type_parameters

[fornit]

Hm,

it should be possible to derive the content of the codecs section with the help of ffprobe. E.g.:
ffprobe -i video.mp4 -select_streams v:0 -show_streams

Look at the following parameters for the video stream:

• codec_name (e.g.: h264)
• codec_tag_string (e.g.: avc1)
• profile (e.g.: Main)
• level (e.g.: 40)

For h264 the part behind "avc1." seems to be a combination of 2 hex values:

• One for the profile: 42E (Baseline), 4D4 (Main) or 640 (High)
• One for the level: Convert decimal to hex value, e.g.: 40 => 028 (hex)

Combination of h264, avc1, Main, 40 => avc1.4D4028

For the audio it seems to be easier:
codec_name == aac, codec_tag_string == mp4a, profile == LC => mp4a.40.2


Have you looked whether you can let ffmpeg create the m3u8 file? Should be easier to let a software do that job.

[aj-stream]

Thank you both!!

That was exactly the information I was looking for!

[aj-stream]

Thank you fornit,
I did the ffprobe -i command, and here is what I got from the list you mention:

• codec_name=h264
• codec_tag_string=[27][0][0][0]
• profile=Main
• level=30

The codeg_tag_string is the one I have no idea what's going on with it.

Any idea if the problem is up-stream when I am re-encoding?

Hm,

it should be possible to derive the content of the codecs section with the help of ffprobe. E.g.:
ffprobe -i video.mp4 -select_streams v:0 -show_streams

Look at the following parameters for the video stream:

• codec_name (e.g.: h264)
• codec_tag_string (e.g.: avc1)
• profile (e.g.: Main)
• level (e.g.: 40)