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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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 | /* * Linear conversion Plug-In * Copyright (c) 1999 by Jaroslav Kysela <perex@suse.cz>, * Abramo Bagnara <abramo@alsa-project.org> * * * This library is free software; you can redistribute it and/or modify * it under the terms of the GNU Library General Public License as * published by the Free Software Foundation; either version 2 of * the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Library General Public License for more details. * * You should have received a copy of the GNU Library General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * */ #include <sound/driver.h> #include <linux/time.h> #include <sound/core.h> #include <sound/pcm.h> #include "pcm_plugin.h" /* * Basic linear conversion plugin */ typedef struct linear_private_data { int conv; } linear_t; static void convert(snd_pcm_plugin_t *plugin, const snd_pcm_plugin_channel_t *src_channels, snd_pcm_plugin_channel_t *dst_channels, snd_pcm_uframes_t frames) { #define CONV_LABELS #include "plugin_ops.h" #undef CONV_LABELS linear_t *data = (linear_t *)plugin->extra_data; void *conv = conv_labels[data->conv]; int channel; int nchannels = plugin->src_format.channels; for (channel = 0; channel < nchannels; ++channel) { char *src; char *dst; int src_step, dst_step; snd_pcm_uframes_t frames1; if (!src_channels[channel].enabled) { if (dst_channels[channel].wanted) snd_pcm_area_silence(&dst_channels[channel].area, 0, frames, plugin->dst_format.format); dst_channels[channel].enabled = 0; continue; } dst_channels[channel].enabled = 1; src = src_channels[channel].area.addr + src_channels[channel].area.first / 8; dst = dst_channels[channel].area.addr + dst_channels[channel].area.first / 8; src_step = src_channels[channel].area.step / 8; dst_step = dst_channels[channel].area.step / 8; frames1 = frames; while (frames1-- > 0) { goto *conv; #define CONV_END after #include "plugin_ops.h" #undef CONV_END after: src += src_step; dst += dst_step; } } } static snd_pcm_sframes_t linear_transfer(snd_pcm_plugin_t *plugin, const snd_pcm_plugin_channel_t *src_channels, snd_pcm_plugin_channel_t *dst_channels, snd_pcm_uframes_t frames) { linear_t *data; snd_assert(plugin != NULL && src_channels != NULL && dst_channels != NULL, return -ENXIO); data = (linear_t *)plugin->extra_data; if (frames == 0) return 0; #ifdef CONFIG_SND_DEBUG { unsigned int channel; for (channel = 0; channel < plugin->src_format.channels; channel++) { snd_assert(src_channels[channel].area.first % 8 == 0 && src_channels[channel].area.step % 8 == 0, return -ENXIO); snd_assert(dst_channels[channel].area.first % 8 == 0 && dst_channels[channel].area.step % 8 == 0, return -ENXIO); } } #endif convert(plugin, src_channels, dst_channels, frames); return frames; } int conv_index(int src_format, int dst_format) { int src_endian, dst_endian, sign, src_width, dst_width; sign = (snd_pcm_format_signed(src_format) != snd_pcm_format_signed(dst_format)); #ifdef SNDRV_LITTLE_ENDIAN src_endian = snd_pcm_format_big_endian(src_format); dst_endian = snd_pcm_format_big_endian(dst_format); #else src_endian = snd_pcm_format_little_endian(src_format); dst_endian = snd_pcm_format_little_endian(dst_format); #endif if (src_endian < 0) src_endian = 0; if (dst_endian < 0) dst_endian = 0; src_width = snd_pcm_format_width(src_format) / 8 - 1; dst_width = snd_pcm_format_width(dst_format) / 8 - 1; return src_width * 32 + src_endian * 16 + sign * 8 + dst_width * 2 + dst_endian; } int snd_pcm_plugin_build_linear(snd_pcm_plug_t *plug, snd_pcm_plugin_format_t *src_format, snd_pcm_plugin_format_t *dst_format, snd_pcm_plugin_t **r_plugin) { int err; struct linear_private_data *data; snd_pcm_plugin_t *plugin; snd_assert(r_plugin != NULL, return -ENXIO); *r_plugin = NULL; snd_assert(src_format->rate == dst_format->rate, return -ENXIO); snd_assert(src_format->channels == dst_format->channels, return -ENXIO); snd_assert(snd_pcm_format_linear(src_format->format) && snd_pcm_format_linear(dst_format->format), return -ENXIO); err = snd_pcm_plugin_build(plug, "linear format conversion", src_format, dst_format, sizeof(linear_t), &plugin); if (err < 0) return err; data = (linear_t *)plugin->extra_data; data->conv = conv_index(src_format->format, dst_format->format); plugin->transfer = linear_transfer; *r_plugin = plugin; return 0; } |