Reading PCM Audio from a Video Container
4 views (last 30 days)
Show older comments
I can successfully read 16-bit PCM Audio data from a .wav file using the 'native' flag using audioread():
>> wav1 = audioread("audioOnly.wav", 'native');
>> whos wav1
Name Size Bytes Class Attributes
wav1 2868224x1 5736448 int16
>> nfo1 = audioinfo('audioOnly.wav')
nfo1 =
struct with fields:
Filename: '...\audioOnly.wav'
CompressionMethod: 'Uncompressed'
NumChannels: 1
SampleRate: 44100
TotalSamples: 2868224
Duration: 65.0390929705215
Title: []
Comment: []
Artist: []
BitsPerSample: 16
>> [min(wav1) max(wav1)]
ans =
1×2 int16 row vector
-32768 32767
This results in the expected int16 data set.
However, if I attempt to apply the 'native' flag when reading audio from a video container such as .avi, I always seem to end up with a normalized single instead of an int16, just as if I was not applying the 'native' flag:
>> wav2 = audioread("audioVideo.avi", 'native');
>> whos wav2
Name Size Bytes Class Attributes
wav2 2868136x1 11472544 single
>> nfo2 = audioinfo('audioVideo.avi')
nfo2 =
struct with fields:
Filename: '...\audioVideo.avi'
CompressionMethod: 'Uncompressed'
NumChannels: 1
SampleRate: 44100
TotalSamples: 2868224
Duration: 65.0390929
Title: []
Comment: []
Artist: []
BitsPerSample: 16
>> [min(wav2) max(wav2)]
ans =
1×2 single row vector
-1 0.9999695
I'm confident that that .avi container has 16-bit uncompressed PCM audio data (it was generated from the original .wav audio data) and I've verified this via ffmpeg externally from MATLAB.
...So what am I misunderstanding about why MATLAB is returning a single to me rather than the expected int16 native data?
0 Comments
Answers (0)
See Also
Categories
Find more on Audio and Video Data in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!