| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame^] | 1 | /* |
| 2 | * Linear conversion Plug-In |
| 3 | * Copyright (c) 2000 by Abramo Bagnara <abramo@alsa-project.org> |
| 4 | * |
| 5 | * |
| 6 | * This library is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU Library General Public License as |
| 8 | * published by the Free Software Foundation; either version 2 of |
| 9 | * the License, or (at your option) any later version. |
| 10 | * |
| 11 | * This program is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | * GNU Library General Public License for more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU Library General Public |
| 17 | * License along with this library; if not, write to the Free Software |
| 18 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 19 | * |
| 20 | */ |
| 21 | |
| 22 | #include <sound/driver.h> |
| 23 | #include <linux/time.h> |
| 24 | #include <sound/core.h> |
| 25 | #include <sound/pcm.h> |
| 26 | #include "pcm_plugin.h" |
| 27 | |
| 28 | static snd_pcm_sframes_t copy_transfer(snd_pcm_plugin_t *plugin, |
| 29 | const snd_pcm_plugin_channel_t *src_channels, |
| 30 | snd_pcm_plugin_channel_t *dst_channels, |
| 31 | snd_pcm_uframes_t frames) |
| 32 | { |
| 33 | unsigned int channel; |
| 34 | unsigned int nchannels; |
| 35 | |
| 36 | snd_assert(plugin != NULL && src_channels != NULL && dst_channels != NULL, return -ENXIO); |
| 37 | if (frames == 0) |
| 38 | return 0; |
| 39 | nchannels = plugin->src_format.channels; |
| 40 | for (channel = 0; channel < nchannels; channel++) { |
| 41 | snd_assert(src_channels->area.first % 8 == 0 && |
| 42 | src_channels->area.step % 8 == 0, |
| 43 | return -ENXIO); |
| 44 | snd_assert(dst_channels->area.first % 8 == 0 && |
| 45 | dst_channels->area.step % 8 == 0, |
| 46 | return -ENXIO); |
| 47 | if (!src_channels->enabled) { |
| 48 | if (dst_channels->wanted) |
| 49 | snd_pcm_area_silence(&dst_channels->area, 0, frames, plugin->dst_format.format); |
| 50 | dst_channels->enabled = 0; |
| 51 | continue; |
| 52 | } |
| 53 | dst_channels->enabled = 1; |
| 54 | snd_pcm_area_copy(&src_channels->area, 0, &dst_channels->area, 0, frames, plugin->src_format.format); |
| 55 | src_channels++; |
| 56 | dst_channels++; |
| 57 | } |
| 58 | return frames; |
| 59 | } |
| 60 | |
| 61 | int snd_pcm_plugin_build_copy(snd_pcm_plug_t *plug, |
| 62 | snd_pcm_plugin_format_t *src_format, |
| 63 | snd_pcm_plugin_format_t *dst_format, |
| 64 | snd_pcm_plugin_t **r_plugin) |
| 65 | { |
| 66 | int err; |
| 67 | snd_pcm_plugin_t *plugin; |
| 68 | int width; |
| 69 | |
| 70 | snd_assert(r_plugin != NULL, return -ENXIO); |
| 71 | *r_plugin = NULL; |
| 72 | |
| 73 | snd_assert(src_format->format == dst_format->format, return -ENXIO); |
| 74 | snd_assert(src_format->rate == dst_format->rate, return -ENXIO); |
| 75 | snd_assert(src_format->channels == dst_format->channels, return -ENXIO); |
| 76 | |
| 77 | width = snd_pcm_format_physical_width(src_format->format); |
| 78 | snd_assert(width > 0, return -ENXIO); |
| 79 | |
| 80 | err = snd_pcm_plugin_build(plug, "copy", src_format, dst_format, |
| 81 | 0, &plugin); |
| 82 | if (err < 0) |
| 83 | return err; |
| 84 | plugin->transfer = copy_transfer; |
| 85 | *r_plugin = plugin; |
| 86 | return 0; |
| 87 | } |