Simple audio playback using ALSA
Utilize ALSA to play an unbuffered raw WAV/PCM sample using x86 Linux assembler (NASM)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 | ; Simple ALSA playback system ; Author: Wesley Stessens (wesley@ubuntu.com) ; ; This ALSA playback system is meant to play only small chunks of PCM data! ; It doesn't use any buffering and is implemented in blocking-mode. ; Therefore it must run in a seperate thread. extern snd_pcm_open, snd_pcm_hw_params_malloc, snd_pcm_hw_params_any, snd_pcm_hw_params_set_access extern snd_pcm_hw_params_set_format, snd_pcm_hw_params_set_rate_near, snd_pcm_hw_params_set_channels extern snd_pcm_hw_params, snd_pcm_hw_params_free extern snd_pcm_prepare, snd_pcm_writei extern snd_pcm_close extern printf SND_PCM_STREAM_PLAYBACK equ 0 SND_PCM_FORMAT_S16_LE equ 2 SND_PCM_ACCESS_RW_INTERLEAVED equ 3 section .data snd incbin "raw_pcm_sample.raw" snd_len equ ($ - snd) / 2 device db "default", 0 section .bss handle resd 1 params resd 1 rate resd 1 playing resb 1 section .text initSound: push dword 0 push dword SND_PCM_STREAM_PLAYBACK push device push handle call snd_pcm_open add esp, 16 push params call snd_pcm_hw_params_malloc add esp, 4 push dword [params] push dword [handle] call snd_pcm_hw_params_any add esp, 8 push dword SND_PCM_ACCESS_RW_INTERLEAVED push dword [params] push dword [handle] call snd_pcm_hw_params_set_access add esp, 12 push dword SND_PCM_FORMAT_S16_LE push dword [params] push dword [handle] call snd_pcm_hw_params_set_format add esp, 12 mov dword [rate], 22050 push dword 0 push rate push dword [params] push dword [handle] call snd_pcm_hw_params_set_rate_near add esp, 16 push dword 1 push dword [params] push dword [handle] call snd_pcm_hw_params_set_channels add esp, 12 push dword [params] push dword [handle] call snd_pcm_hw_params add esp, 8 push dword [params] call snd_pcm_hw_params_free add esp, 4 push dword [handle] call snd_pcm_prepare add esp, 4 mov byte [playing], 0 ret playSound: cmp byte [playing], 1 ; Prevent multiple sounds from playing to eliminate errors je playSound mov byte [playing], 1 push dword snd_len push snd push dword [handle] call snd_pcm_writei add esp, 12 mov byte [playing], 0 ret |
