Bit Rate in an AIFF file

[Dave1024]

Hello,

I would like to know the bit rate of one of my audio file in AIFF format.

This file had 48 K sample rate 16 bit depth and 4 MB audio data.
From this how can i figure out bits per second value?

Does this value can accommodate in any of the chunks of AIFF file ?

:thanks:
Dave

[Asmodian]

I assume this is an uncompressed AIFF? How many seconds long is it? 48000 * 16 = 768,000 bps

[LoRd_MuldeR]

If it's indeed uncompressed PCM, you can assume:
data rate (in bits/second) = channel count × sample rate (in samples/second) × bits per sample

Also, if the file is audio-only, you can assume that:
data rate (in bits/second) = [file size (in bytes) × 8] / duration (in seconds)

Of course the above leaves out the container overhead, so it may not be 100% accurate... But why not simply ask MediaInfo (http://mediaarea.net/en/MediaInfo) or a similar tool?

[Dave1024]

Hi,

I used Media Info.
One of my audio file result given below.
Does this correct?

ID : 1
Format : PCM
Format settings, Endianness : Big
Format settings, Sign : Signed
Muxing mode : AIFF
Codec ID : twos
Duration : 5mn 30s
Bit rate mode : Constant
Bit rate : 69.7 Kbps
Channel(s) : 2 channels
Channel positions : Front: L R
Sampling rate : 48.0 KHz
Bit depth : 16 bits
Stream size : 2.75 MiB (100%)
Language : English

:thanks:
Dave

[LoRd_MuldeR]

How should we know what is correct for your specific file? :confused:

But 2 channels at 48.000 Hz with 16-Bit per sample should result in something like 1536 kbit/s - if it's uncompressed!

(Don't know what Codec ID "twos" means, but if it is some compressed format, there generally is no relation between the data rate of the compressed audio and the sample rate or bit depth that the decoder is going to put out. For example, I can take an uncompressed 44.1 KHz Stereo source with 16 bits/sample and compress it to MP3 at any data rate between 32 kbit/s and 320 kbit/s. And whether the MP3 decoder later is going to output the decoded audio as 16-Bit Integers or 32-Bit Floats is implementation specific. Formats like Opus even resample the audio, so you might not even get the "original" sample rate from the decoder...)

[Dave1024]

Hello,

Really I would like to share this. I am sorry for the mistake.

Audio
Format : PCM
Format_Settings_Endianness : Big
Duration : 5mn 30s
BitRate_Mode : Constant
BitRate : 69.7 Kbps
Channel(s) : 2 channels
SamplingRate : 48.0 KHz
BitDepth : 16 bits
StreamSize : 2.75 MiB (100%)

Here i tried to write a wave to AIFF conversion.
The AIFF file which i created shows the info.
well the required parameters are correct but bit rate is wrong.
Is this a bug in media info.

Thanks
Dave

[filler56789]

Don't know what Codec ID "twos" means

It's a QuickTime thing,

http://wiki.multimedia.cx/index.php?title=QuickTime_container#Audio_FOURCCs

[LoRd_MuldeR]

It's a QuickTime thing,

http://wiki.multimedia.cx/index.php?title=QuickTime_container#Audio_FOURCCs

'twos' denotes signed (i.e. twos-complement) linear PCM. 16-bit data is stored in big endian format.

This would indicate it's simply 16 bit/sample uncompressed PCM. But then the data rate should be 1536 kbit/s, for 48.000 Hz and Stereo...

Is this a bug in media info.

Possible. You may want to file a bug report then:
http://sourceforge.net/p/mediainfo/bugs/

[Dave1024]

Hello,

Seems to be a bug in Media Info. If i put a RIFF header the bit rate is 1536 Kbit/sec Media Info is fine with RIFF.

Thanks
Dave.