Re: [Ekiga-list] A comparison ALSA-PULSE

[Andrea <mariofutire googlemail com>]

Alec Leamas wrote:
> 
>> It is at the beginning of the 2 files (the same):
>>
>> Its setup is:
>>   stream       : PLAYBACK
>>   access       : RW_INTERLEAVED
>>   format       : S16_LE
>>   subformat    : STD
>>   channels     : 2
>>   rate         : 44100
>>   exact rate   : 44100 (44100/1)
>>   msbits       : 16
>>   buffer_size  : 1764
>>   period_size  : 441
>>   period_time  : 10000
>>   tstamp_mode  : NONE
>>   period_step  : 1
>>   avail_min    : 441
>>   period_event : 0
>>   start_threshold  : 1
>>   stop_threshold   : 1764
>>   silence_threshold: 0
>>   silence_size : 0
>>   boundary     : 1849688064
>>
>>   
> Actually, I thnk I'm wrong. If  the buffer is 1764 frames:. Time for 1
> frame = 1/44100 sec = 1000/44100 ms. Time for buffer 1764 * 1000/44100=
> 40 ms. So, it really not that small, and increasing  it is a problem.

Looking at the code in PSoundChannelALSA::Write(), where len=1764

    /* the number of frames to read is the buffer length
       divided by the size of one frame */
    r = snd_pcm_writei (os_handle, (char *) &buf2 [pos], len / frameBytes);

I would say 1764 is a number of bytes.

The header file confirms this

    virtual PBoolean Write(
      const void * buf, ///< Pointer to a block of memory to write.
      PINDEX len        ///< Number of bytes to write.
    );