forked from luck/tmp_suning_uos_patched
9390ec85c0
Simplify the format conversion code in PCM OSS emulation. This patch also adds the support of 3bytes 24bit formats with linear and mulaw, but they are not enabled in pcm_plugin.c yet. Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jaroslav Kysela <perex@suse.cz>
177 lines
5.7 KiB
C
177 lines
5.7 KiB
C
/*
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* Linear conversion Plug-In
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* Copyright (c) 1999 by Jaroslav Kysela <perex@suse.cz>,
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* Abramo Bagnara <abramo@alsa-project.org>
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*
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*
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* This library is free software; you can redistribute it and/or modify
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* it under the terms of the GNU Library General Public License as
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* published by the Free Software Foundation; either version 2 of
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* the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Library General Public License for more details.
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*
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* You should have received a copy of the GNU Library General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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*/
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#include <sound/driver.h>
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#include <linux/time.h>
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#include <sound/core.h>
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#include <sound/pcm.h>
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#include "pcm_plugin.h"
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/*
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* Basic linear conversion plugin
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*/
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struct linear_priv {
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int cvt_endian; /* need endian conversion? */
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unsigned int src_ofs; /* byte offset in source format */
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unsigned int dst_ofs; /* byte soffset in destination format */
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unsigned int copy_ofs; /* byte offset in temporary u32 data */
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unsigned int dst_bytes; /* byte size of destination format */
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unsigned int copy_bytes; /* bytes to copy per conversion */
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unsigned int flip; /* MSB flip for signeness, done after endian conv */
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};
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static inline void do_convert(struct linear_priv *data,
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unsigned char *dst, unsigned char *src)
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{
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unsigned int tmp = 0;
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unsigned char *p = (unsigned char *)&tmp;
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memcpy(p + data->copy_ofs, src + data->src_ofs, data->copy_bytes);
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if (data->cvt_endian)
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tmp = swab32(tmp);
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tmp ^= data->flip;
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memcpy(dst, p + data->dst_ofs, data->dst_bytes);
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}
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static void convert(struct snd_pcm_plugin *plugin,
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const struct snd_pcm_plugin_channel *src_channels,
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struct snd_pcm_plugin_channel *dst_channels,
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snd_pcm_uframes_t frames)
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{
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struct linear_priv *data = (struct linear_priv *)plugin->extra_data;
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int channel;
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int nchannels = plugin->src_format.channels;
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for (channel = 0; channel < nchannels; ++channel) {
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char *src;
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char *dst;
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int src_step, dst_step;
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snd_pcm_uframes_t frames1;
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if (!src_channels[channel].enabled) {
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if (dst_channels[channel].wanted)
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snd_pcm_area_silence(&dst_channels[channel].area, 0, frames, plugin->dst_format.format);
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dst_channels[channel].enabled = 0;
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continue;
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}
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dst_channels[channel].enabled = 1;
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src = src_channels[channel].area.addr + src_channels[channel].area.first / 8;
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dst = dst_channels[channel].area.addr + dst_channels[channel].area.first / 8;
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src_step = src_channels[channel].area.step / 8;
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dst_step = dst_channels[channel].area.step / 8;
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frames1 = frames;
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while (frames1-- > 0) {
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do_convert(data, dst, src);
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src += src_step;
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dst += dst_step;
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}
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}
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}
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static snd_pcm_sframes_t linear_transfer(struct snd_pcm_plugin *plugin,
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const struct snd_pcm_plugin_channel *src_channels,
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struct snd_pcm_plugin_channel *dst_channels,
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snd_pcm_uframes_t frames)
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{
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struct linear_priv *data;
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snd_assert(plugin != NULL && src_channels != NULL && dst_channels != NULL, return -ENXIO);
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data = (struct linear_priv *)plugin->extra_data;
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if (frames == 0)
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return 0;
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#ifdef CONFIG_SND_DEBUG
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{
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unsigned int channel;
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for (channel = 0; channel < plugin->src_format.channels; channel++) {
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snd_assert(src_channels[channel].area.first % 8 == 0 &&
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src_channels[channel].area.step % 8 == 0,
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return -ENXIO);
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snd_assert(dst_channels[channel].area.first % 8 == 0 &&
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dst_channels[channel].area.step % 8 == 0,
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return -ENXIO);
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}
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}
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#endif
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convert(plugin, src_channels, dst_channels, frames);
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return frames;
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}
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static void init_data(struct linear_priv *data, int src_format, int dst_format)
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{
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int src_le, dst_le, src_bytes, dst_bytes;
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src_bytes = snd_pcm_format_width(src_format) / 8;
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dst_bytes = snd_pcm_format_width(dst_format) / 8;
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src_le = snd_pcm_format_little_endian(src_format) > 0;
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dst_le = snd_pcm_format_little_endian(dst_format) > 0;
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data->dst_bytes = dst_bytes;
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data->cvt_endian = src_le != dst_le;
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data->copy_bytes = src_bytes < dst_bytes ? src_bytes : dst_bytes;
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if (src_le) {
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data->copy_ofs = 4 - data->copy_bytes;
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data->src_ofs = src_bytes - data->copy_bytes;
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} else
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data->src_ofs = snd_pcm_format_physical_width(src_format) / 8 -
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src_bytes;
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if (dst_le)
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data->dst_ofs = 4 - data->dst_bytes;
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else
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data->dst_ofs = snd_pcm_format_physical_width(dst_format) / 8 -
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dst_bytes;
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if (snd_pcm_format_signed(src_format) !=
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snd_pcm_format_signed(dst_format)) {
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if (dst_le)
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data->flip = cpu_to_le32(0x80000000);
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else
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data->flip = cpu_to_be32(0x80000000);
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}
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}
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int snd_pcm_plugin_build_linear(struct snd_pcm_substream *plug,
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struct snd_pcm_plugin_format *src_format,
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struct snd_pcm_plugin_format *dst_format,
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struct snd_pcm_plugin **r_plugin)
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{
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int err;
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struct linear_priv *data;
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struct snd_pcm_plugin *plugin;
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snd_assert(r_plugin != NULL, return -ENXIO);
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*r_plugin = NULL;
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snd_assert(src_format->rate == dst_format->rate, return -ENXIO);
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snd_assert(src_format->channels == dst_format->channels, return -ENXIO);
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snd_assert(snd_pcm_format_linear(src_format->format) &&
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snd_pcm_format_linear(dst_format->format), return -ENXIO);
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err = snd_pcm_plugin_build(plug, "linear format conversion",
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src_format, dst_format,
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sizeof(struct linear_priv), &plugin);
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if (err < 0)
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return err;
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data = (struct linear_priv *)plugin->extra_data;
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init_data(data, src_format->format, dst_format->format);
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plugin->transfer = linear_transfer;
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*r_plugin = plugin;
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return 0;
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}
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