linuxaudio.org

On Fri, 1 Apr 2011, Robin Gareus wrote:
>

quoted text
>> However, for piping jack-stdout just got options for 24 bits, while jack_capture still only supports 16 bits.

>

> See the announce from today. jack-stdio supports 8/16/24/32 bit integer,

> both big and little endian, as well as 32 bit float (both native-endian

> as well as swapped endianess).

>

> @Kjetil:

> Does jack_capture buffer the [processed] data before I/O? jack-stdio does not.

> jack-stdin/out reads/writes one sample at a time, and thus is relatively heavy on the CPU

> (3-5% on a 2GHz machine - quite a lot for a such a small tool).

>

jack_capture writes blocks at the time:
   int bytes_to_write=frames*num_channels*2;

   {

     int i;

     int writeplace=0;

     for(i=0;i>8)&0xff);

     }

   }

   {

     int fd=fileno(stdout);

     while(bytes_to_write > 0){

       int written=write(fd,tobuffer,bytes_to_write);

       if(written==-1){

 	fprintf(stderr,"Error writing to stdout.\n");

 	break;

       }

       bytes_to_write -= written;

     }

   }
>> The reason why jack_capture lags a bit behind here is probably because

quoted text
>> jack_capture used code from jack-stdout to implement writing to stdout.

>> :-)

>

> Before you look into merging it: I just have spotted a bug with endianess for PPC/ big-endian architectures.

> all the #ifdef __BIG_ENDIAN__ code can go away:  The compiler (at least gcc) does swap

> constants 0x00ff <> 0xff00 and indices for uint8_t.

>

Thanks.
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