cregit-Linux how code gets into the kernel

Release 4.11 sound/core/oss/linear.c

Directory: sound/core/oss
/*
 *  Linear conversion Plug-In
 *  Copyright (c) 1999 by Jaroslav Kysela <perex@perex.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 <linux/time.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include "pcm_plugin.h"

/*
 *  Basic linear conversion plugin
 */
 

struct linear_priv {
	
int cvt_endian;		/* need endian conversion? */
	
unsigned int src_ofs;	/* byte offset in source format */
	
unsigned int dst_ofs;	/* byte soffset in destination format */
	
unsigned int copy_ofs;	/* byte offset in temporary u32 data */
	
unsigned int dst_bytes;		/* byte size of destination format */
	
unsigned int copy_bytes;	/* bytes to copy per conversion */
	
unsigned int flip; /* MSB flip for signeness, done after endian conv */
};


static inline void do_convert(struct linear_priv *data, unsigned char *dst, unsigned char *src) { unsigned int tmp = 0; unsigned char *p = (unsigned char *)&tmp; memcpy(p + data->copy_ofs, src + data->src_ofs, data->copy_bytes); if (data->cvt_endian) tmp = swab32(tmp); tmp ^= data->flip; memcpy(dst, p + data->dst_ofs, data->dst_bytes); }

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Takashi Iwai94100.00%1100.00%
Total94100.00%1100.00%


static void convert(struct snd_pcm_plugin *plugin, const struct snd_pcm_plugin_channel *src_channels, struct snd_pcm_plugin_channel *dst_channels, snd_pcm_uframes_t frames) { struct linear_priv *data = (struct linear_priv *)plugin->extra_data; 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) { do_convert(data, dst, src); src += src_step; dst += dst_step; } } }

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PersonTokensPropCommitsCommitProp
Jaroslav Kysela22492.18%133.33%
Takashi Iwai197.82%266.67%
Total243100.00%3100.00%


static snd_pcm_sframes_t linear_transfer(struct snd_pcm_plugin *plugin, const struct snd_pcm_plugin_channel *src_channels, struct snd_pcm_plugin_channel *dst_channels, snd_pcm_uframes_t frames) { if (snd_BUG_ON(!plugin || !src_channels || !dst_channels)) return -ENXIO; if (frames == 0) return 0; #ifdef CONFIG_SND_DEBUG { unsigned int channel; for (channel = 0; channel < plugin->src_format.channels; channel++) { if (snd_BUG_ON(src_channels[channel].area.first % 8 || src_channels[channel].area.step % 8)) return -ENXIO; if (snd_BUG_ON(dst_channels[channel].area.first % 8 || dst_channels[channel].area.step % 8)) return -ENXIO; } } #endif convert(plugin, src_channels, dst_channels, frames); return frames; }

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Jaroslav Kysela8251.90%133.33%
Takashi Iwai7648.10%266.67%
Total158100.00%3100.00%


static void init_data(struct linear_priv *data, snd_pcm_format_t src_format, snd_pcm_format_t dst_format) { int src_le, dst_le, src_bytes, dst_bytes; src_bytes = snd_pcm_format_width(src_format) / 8; dst_bytes = snd_pcm_format_width(dst_format) / 8; src_le = snd_pcm_format_little_endian(src_format) > 0; dst_le = snd_pcm_format_little_endian(dst_format) > 0; data->dst_bytes = dst_bytes; data->cvt_endian = src_le != dst_le; data->copy_bytes = src_bytes < dst_bytes ? src_bytes : dst_bytes; if (src_le) { data->copy_ofs = 4 - data->copy_bytes; data->src_ofs = src_bytes - data->copy_bytes; } else data->src_ofs = snd_pcm_format_physical_width(src_format) / 8 - src_bytes; if (dst_le) data->dst_ofs = 4 - data->dst_bytes; else data->dst_ofs = snd_pcm_format_physical_width(dst_format) / 8 - dst_bytes; if (snd_pcm_format_signed(src_format) != snd_pcm_format_signed(dst_format)) { if (dst_le) data->flip = (__force u32)cpu_to_le32(0x80000000); else data->flip = (__force u32)cpu_to_be32(0x80000000); } }

Contributors

PersonTokensPropCommitsCommitProp
Takashi Iwai13466.67%250.00%
Jaroslav Kysela5728.36%125.00%
Clemens Ladisch104.98%125.00%
Total201100.00%4100.00%


int snd_pcm_plugin_build_linear(struct snd_pcm_substream *plug, struct snd_pcm_plugin_format *src_format, struct snd_pcm_plugin_format *dst_format, struct snd_pcm_plugin **r_plugin) { int err; struct linear_priv *data; struct snd_pcm_plugin *plugin; if (snd_BUG_ON(!r_plugin)) return -ENXIO; *r_plugin = NULL; if (snd_BUG_ON(src_format->rate != dst_format->rate)) return -ENXIO; if (snd_BUG_ON(src_format->channels != dst_format->channels)) return -ENXIO; if (snd_BUG_ON(!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(struct linear_priv), &plugin); if (err < 0) return err; data = (struct linear_priv *)plugin->extra_data; init_data(data, src_format->format, dst_format->format); plugin->transfer = linear_transfer; *r_plugin = plugin; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Jaroslav Kysela10355.98%125.00%
Takashi Iwai8144.02%375.00%
Total184100.00%4100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Jaroslav Kysela48551.98%337.50%
Takashi Iwai43846.95%450.00%
Clemens Ladisch101.07%112.50%
Total933100.00%8100.00%
Directory: sound/core/oss
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