WIP: First dig at reading WAV PCM samples from pipe, addressing #80

[davidavdav]

Hi,

For PCM wav streams I've made a start to address #80, so this is just to gauge your opinion on the approach.

Things that still need to be taken care of are

• Add support for reading from pipe for other data formats
• Add support for subrange specification (by properly implementing skip and limited reading)
• Somehow add sox as a test dependency

[dancasimiro]

This looks reasonable, but there are some subtle changes in the handling of bytes. Do you need to make the low level byte changes for sox to function?

[dancasimiro]

Why did this call switch from read! to read?

[davidavdav]

In the original code, the length of the data to be read was known, and could be declared in advance. In the case of reading from a pipe, this won't work as way too too much memory is reserved if the process writing to the pipe has lied about the length (as is the case for sox).

I further changed the read! to read in the non-pipe reading case. I assumed that it does not make a difference in efficiency where the memory is declared, since the implementation of read(::IO, len::Int) declares the memory just like in the original code, and then does the readbytes!().

[dancasimiro]

Alright.

Am I correct that this code depends on the other process being well behaved?

[dancasimiro]

@davidavdav: Is there still interest in pursuing this pull request? If not, I would like to close it.

[davidavdav]

I would still argue it should be possible to read from pipe, but unfortunately I haven't been in the opportunity to use Julia for work much, so I am fine with leaving this PR in limbo for another while