| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | Recording |
| 2 | --------- |
| 3 | |
| 4 | Recording does not work on the author's card, but there |
| 5 | is at least one report of it working on later silicon. |
| 6 | The chip behaves differently than described in the data sheet, |
| 7 | likely due to a chip bug. Working around this would require |
| 8 | the help of ESS (for example by publishing an errata sheet), |
| 9 | but ESS has not done so so far. |
| 10 | |
| 11 | Also, the chip only supports 24 bit addresses for recording, |
| 12 | which means it cannot work on some Alpha mainboards. |
| 13 | |
| 14 | |
| 15 | /proc/sound, /dev/sndstat |
| 16 | ------------------------- |
| 17 | |
| 18 | /proc/sound and /dev/sndstat is not supported by the |
| 19 | driver. To find out whether the driver succeeded loading, |
| 20 | check the kernel log (dmesg). |
| 21 | |
| 22 | |
| 23 | ALaw/uLaw sample formats |
| 24 | ------------------------ |
| 25 | |
| 26 | This driver does not support the ALaw/uLaw sample formats. |
| 27 | ALaw is the default mode when opening a sound device |
| 28 | using OSS/Free. The reason for the lack of support is |
| 29 | that the hardware does not support these formats, and adding |
| 30 | conversion routines to the kernel would lead to very ugly |
| 31 | code in the presence of the mmap interface to the driver. |
| 32 | And since xquake uses mmap, mmap is considered important :-) |
| 33 | and no sane application uses ALaw/uLaw these days anyway. |
| 34 | In short, playing a Sun .au file as follows: |
| 35 | |
| 36 | cat my_file.au > /dev/dsp |
| 37 | |
| 38 | does not work. Instead, you may use the play script from |
| 39 | Chris Bagwell's sox-12.14 package (or later, available from the URL |
| 40 | below) to play many different audio file formats. |
| 41 | The script automatically determines the audio format |
| 42 | and does do audio conversions if necessary. |
| 43 | http://home.sprynet.com/sprynet/cbagwell/projects.html |
| 44 | |
| 45 | |
| 46 | Blocking vs. nonblocking IO |
| 47 | --------------------------- |
| 48 | |
| 49 | Unlike OSS/Free this driver honours the O_NONBLOCK file flag |
| 50 | not only during open, but also during read and write. |
| 51 | This is an effort to make the sound driver interface more |
| 52 | regular. Timidity has problems with this; a patch |
| 53 | is available from http://www.ife.ee.ethz.ch/~sailer/linux/pciaudio.html. |
| 54 | (Timidity patched will also run on OSS/Free). |
| 55 | |
| 56 | |
| 57 | MIDI UART |
| 58 | --------- |
| 59 | |
| 60 | The driver supports a simple MIDI UART interface, with |
| 61 | no ioctl's supported. |
| 62 | |
| 63 | |
| 64 | MIDI synthesizer |
| 65 | ---------------- |
| 66 | |
| 67 | The card has an OPL compatible FM synthesizer. |
| 68 | |
| 69 | Thomas Sailer |
| 70 | t.sailer@alumni.ethz.ch |