Why a VCD do not have the 1440 kbps audio CD bitrate.

[anonymoustly]

Why VCD have a lower bitrate of 1374 kbps than audio CD? I canot understand that because both hold 80 minutes of content.

[DB83]

Two reasons.


1. There must be room for the video and other files
2. The compression of audio CD and the audio part of a VCD is different. The former is uncompressed LPCM and the latter is compressed Mpeg.


Your 1374 kbps is wrong. The max is 384 kbps.


Assuming, of course, we are both talking about a Video CD. Does VCD stand for something else as well ?

[anonymoustly]

Huh?? 1150 + 224 = 1374

What is the difference it is a 320 kbps Mp3, ogg, h265, mpeg2 or wav file?

[DB83]

Why are you bothered ? VCD is a legacy format now.

[aedipuss]

vcd has to allow for things like closed captions, multipexing overhead, etc. mp3, ogg, h265 and wav are not allowed by the vcd spec.

[Skiller]

Like any container format (yes, even modern ones such as MKV and MP4), the file size is larger than the sum of the elementary video and audio streams. It's called overhead and it's where the "missing" bits come from. Audio CDs don't have that.


Edit: More like this but don't quote me on the total bitrate (1411):

1150 + 224 + 37 = 1411

Where is your 1440 kbps actually coming from? I don't recall that number.

[Quint]

Additionally the quite old Audio-CD-(low-level-)format hasn't got the same redundancies for error correction as later digital formats.

[anonymoustly]

Like any container format (yes, even modern ones such as MKV and MP4), the file size is larger than the sum of the elementary video and audio streams. It's called overhead and it's where the "missing" bits come from. Audio CDs don't have that.


Edit: More like this but don't quote me on the total bitrate (1411):

1150 + 224 + 37 = 1411

Where is your 1440 kbps actually coming from? I don't recall that number.

mean with 1440 audio CD = 1,411 sorry!

[Cornucopia]

Audio on audio CD = 16bit, 2ch, 44.1kHz. 16 * 2 * 44100 = 1,411,200 bits/sec or 1,411.2 kbps (if using 1000base). Or 1,378.125kbps (if using 1024 base). The actual disc data bitrate is slightly higher because of presence of subcode, and this ALL has reed-solomon error correction, so 1500 is an easy round number to remember for the 1x CD overall data rate.
Something tells me that you aren't into rounding, though.


Scott

[anonymoustly]

Like any container format (yes, even modern ones such as MKV and MP4), the file size is larger than the sum of the elementary video and audio streams. It's called overhead and it's where the "missing" bits come from. Audio CDs don't have that.


Edit: More like this but don't quote me on the total bitrate (1411):

1150 + 224 + 37 = 1411

Where is your 1440 kbps actually coming from? I don't recall that number.

Think it is from a real 1080p 4:3 aspect ratio video, who is 1440x1080 pixels. although that video format is very rare.

[Quint]

What nonsense.
Don't feed the trolls. Learned this back in 1997 in newsgroups.