Understanding Profiles

[whereswally007]

Hey everyone,

I would like to know more information on h.264 profiles and converting.

h.264 profile: High 10 @L5.1
I would like to understand what each part means.

Also when i convert this file from 10bit to 8bit, the file goes from 1.8GB to 900MB. I thought when you converted 10bit to 8bit the size of the file was meant to increase.

I check the information (before and after shown below When converting have i lost quality (if so how much/ will it make a difference).

10bit file

A track
track number: 1 (track ID for mkvmerge & mkvextract : 0)
track UID: 1
Track type: video
Lacing flac: 0
mincache: 1
codec iD: V_MPEG4/ISO/AVC
codecPrivate, length 45 (h.264 profile: high 10 @L5.1)
default duration: 41.705ms (23.976 frames/fields per second for a video track)
video track
pixel width: 1920
pixel height: 1080
display width: 1920
display height:1080

A track
track number: 2 (track ID for mkvmerge & mkvextract : 1)
track UID: 171
Track type: audio
codec iD: A_FLAC
codecPrivate, length 113
default duration: 85.333ms (11.719 frames/fields per second for a video track)
name: 5.1 FLAC 24bit
audio track
sampling frequency: 48000
channels: 6
bit depth: 24



8bit file

A track
track number: 3 (track ID for mkvmerge & mkvextract : 2)
track UID: 1
Track type: video
Lacing flac: 0
mincache: 1
codec iD: V_MPEG4/ISO/AVC
codecPrivate, length 42 (h.264 profile: high @L4.0)
video track
pixel width: 1920
pixel height: 1080
display width: 1920
display height:1080

A track
track number: 1 (track ID for mkvmerge & mkvextract : 0)
track UID: 171
Track type: audio
codec iD: A_FLAC
codecPrivate, length 113
default duration: 85.333ms (11.719 frames/fields per second for a video track)
name: 5.1 FLAC 24bit
audio track
sampling frequency: 48000
channels: 6
bit depth: 24

Only difference i can see is the "codecPrivate, length 45 (h.264 profile: high 10 @L5.1)" - "codecPrivate, length 42 (h.264 profile: high @L4.0)"

[jagabo]

https://en.wikipedia.org/wiki/H.264#Profiles
https://en.wikipedia.org/wiki/H.264#Levels
file size = bitrate * running time (plus a little overhead for the container)

[Selur]

"plus a little overhead for the container"
depending on the container the overhead might be more than two times the size of the raw files.

[jagabo]

The OP is working with 1080p video. There is no container that will give 2x overhead for any reasonable bitrate for that. We're talking about 1 percent for most containers.

[Selur]

okay, not wanting to go into the discussion what might be a reasonable bit rate.