[linux-audio-user] extract and mix

[Brad Fuller]

Mark Knecht wrote:

>On 12/19/05, Brad Fuller <brad at sonaural.com> wrote:
>  
>
>>Brad Fuller wrote:
>>
>>    
>>
>>>Brad Fuller wrote:
>>>
>>>      
>>>
>>>>I couldn't find a way to do this in ecasound, maybe there's a way to
>>>>do it. Here's what I want to do:
>>>>
>>>>Find the exact length of a audio file in ms. I think ecalength can do
>>>>this, I know it's not sample accurate, but I just need down to the
>>>>around 1ms. Maybe there's another option other than ecalength.
>>>>        
>>>>
>
>sndfile-info?
>
>mark at lightning ~ $ sndfile-info Web-music/2AM-40Bars.wav
>
>Version : libsndfile-1.0.11
>
>========================================
>File : Web-music/2AM-40Bars.wav
>Length : 35744300
>RIFF : 35744292
>WAVE
>fmt  : 16
>  Format        : 0x1 => WAVE_FORMAT_PCM
>  Channels      : 2
>  Sample Rate   : 44100
>  Block Align   : 6
>  Bit Width     : 24
>  Bytes/sec     : 264600
>data : 35744256
>End
>
>----------------------------------------
>Sample Rate : 44100
>Frames      : 5957376
>Channels    : 2
>Format      : 0x00010003
>Sections    : 1
>Seekable    : TRUE
>Duration    : 00:02:15.087
>Signal Max  : 7.50863e+06 (-0.96 dB)
>
>mark at lightning ~ $
>
>I cannot help with the rest. Sorry.
>  
>
Thanks mark.  I was hoping that there was a utility that I could use in 
a script as I have to do this many many times. I guess I could grep for 
"Duration<tab>: " and grab the numbers.

brad

>- Mark
>  
>
>>>>Then, I want to extract a section of another file: at a specific
>>>>location in ms at a length of the file above.
>>>>
>>>>Then, mix that extracted segment with another file and save the
>>>>result to a new file.  How can this be done? I don't know of a
>>>>utility that can extract a specific length at a specific location in ms.
>>>>
>>>>brad
>>>>
>>>>
>>>>        
>>>>
>>>I forgot all about sox - looks like I could use sox to essentially
>>>extract a section by using the feature "trim start length"
>>>      
>>>
>>does anyone have any ideas on how I can accomplish this process? Has
>>anyone used the "trim" feature in sox?
>>Also, I like to be able to extract the file section (step 2 above) to
>>the nearest zero crossing (to prevent potential clicks). Any pointers,
>>even off the top of your head, would be most appreciated.
>>
>>thanks,
>>
>>    
>>