diff options
Diffstat (limited to 'sound/core/oss/copy.c')
-rw-r--r-- | sound/core/oss/copy.c | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/sound/core/oss/copy.c b/sound/core/oss/copy.c new file mode 100644 index 00000000000..edecbe7417b --- /dev/null +++ b/sound/core/oss/copy.c @@ -0,0 +1,87 @@ +/* + * Linear conversion Plug-In + * Copyright (c) 2000 by 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" + +static snd_pcm_sframes_t copy_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) +{ + unsigned int channel; + unsigned int nchannels; + + snd_assert(plugin != NULL && src_channels != NULL && dst_channels != NULL, return -ENXIO); + if (frames == 0) + return 0; + nchannels = plugin->src_format.channels; + for (channel = 0; channel < nchannels; channel++) { + snd_assert(src_channels->area.first % 8 == 0 && + src_channels->area.step % 8 == 0, + return -ENXIO); + snd_assert(dst_channels->area.first % 8 == 0 && + dst_channels->area.step % 8 == 0, + return -ENXIO); + if (!src_channels->enabled) { + if (dst_channels->wanted) + snd_pcm_area_silence(&dst_channels->area, 0, frames, plugin->dst_format.format); + dst_channels->enabled = 0; + continue; + } + dst_channels->enabled = 1; + snd_pcm_area_copy(&src_channels->area, 0, &dst_channels->area, 0, frames, plugin->src_format.format); + src_channels++; + dst_channels++; + } + return frames; +} + +int snd_pcm_plugin_build_copy(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; + snd_pcm_plugin_t *plugin; + int width; + + snd_assert(r_plugin != NULL, return -ENXIO); + *r_plugin = NULL; + + snd_assert(src_format->format == dst_format->format, return -ENXIO); + snd_assert(src_format->rate == dst_format->rate, return -ENXIO); + snd_assert(src_format->channels == dst_format->channels, return -ENXIO); + + width = snd_pcm_format_physical_width(src_format->format); + snd_assert(width > 0, return -ENXIO); + + err = snd_pcm_plugin_build(plug, "copy", src_format, dst_format, + 0, &plugin); + if (err < 0) + return err; + plugin->transfer = copy_transfer; + *r_plugin = plugin; + return 0; +} |