460b9539 |
1 | * DisOrder Raw Format Players |
2 | |
3 | ** Purpose |
4 | |
5 | The purpose of raw format players is: |
6 | |
7 | * Support pausing of playing tracks, with the audio device closed when not |
8 | in active use. |
9 | |
10 | * Eliminate the inter-track gap. |
11 | |
12 | * Perhaps in the future support network play. |
13 | |
14 | ** Usage |
15 | |
16 | To use raw format, use the execraw module and make the command choose the |
17 | "disorder" libao driver. |
18 | |
19 | You should pass the "fragile" option to ogg123. This is because ogg123 ignores |
20 | write errors! |
21 | |
22 | mpg321 does not appear to have this bug. |
23 | |
24 | For _non_ raw players it is advisable to use the new --wait-for-device option. |
25 | This repeatedly tries to open the audio device before starting the player |
26 | proper. It times out after a couple of seconds. |
27 | |
28 | See disorder_config(5) and the example configuration file for further |
29 | information and examples. |
30 | |
31 | ** Low-Level Details |
32 | |
33 | Raw format players are started slightly differently to normal ones. Before |
34 | they are executed a pipe is created and one end passed to a special speaker |
35 | process, which is spawned by the main server at startup. The file descriptor |
36 | of the player's end is identified by $DISORDER_RAW_FD. |
37 | |
38 | The expected data format is a ao_sample_format structure followed by the raw |
39 | sample data. However, this may be changed without notice in future versions of |
40 | DisOrder. If you need a stable interface here for some reason then get in |
41 | touch. |
42 | |
43 | Raw format players may be started before the track is to be played, and (if the |
44 | track is then removed from the queue before it reaches the head) terminated |
45 | before the track ever reaches a physical speaker. The point of this is to |
46 | allow audio data to be ready to play the moment the previous track end, without |
47 | having to wait for the player to start up. There is no way for a player to |
48 | tell that this is going on. |
49 | |
50 | Local Variables: |
51 | mode:outline |
52 | fill-column:79 |
53 | End: |