2  *  Rate conversion Plug-In
18  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
29 #define R_MASK	(BITS-1)
55 	unsigned int channel;  in rate_init()  local
56 	struct rate_priv *data = (struct rate_priv *)plugin->extra_data;  in rate_init()
57 	data->pos = 0;  in rate_init()
58 	for (channel = 0; channel < plugin->src_format.channels; channel++) {  in rate_init()
59 		data->channels[channel].last_S1 = 0;  in rate_init()
60 		data->channels[channel].last_S2 = 0;  in rate_init()
73 	unsigned int channel;  in resample_expand()  local
76 	struct rate_priv *data = (struct rate_priv *)plugin->extra_data;  in resample_expand()
77 	struct rate_channel *rchannels = data->channels;  in resample_expand()
79 	for (channel = 0; channel < plugin->src_format.channels; channel++) {  in resample_expand()
80 		pos = data->pos;  in resample_expand()
81 		S1 = rchannels->last_S1;  in resample_expand()
82 		S2 = rchannels->last_S2;  in resample_expand()
83 		if (!src_channels[channel].enabled) {  in resample_expand()
84 			if (dst_channels[channel].wanted)  in resample_expand()
85 				snd_pcm_area_silence(&dst_channels[channel].area, 0, dst_frames, plugin->dst_format.format);  in resample_expand()
86 			dst_channels[channel].enabled = 0;  in resample_expand()
89 		dst_channels[channel].enabled = 1;  in resample_expand()
90 		src = (signed short *)src_channels[channel].area.addr +  in resample_expand()
91 			src_channels[channel].area.first / 8 / 2;  in resample_expand()
92 		dst = (signed short *)dst_channels[channel].area.addr +  in resample_expand()
93 			dst_channels[channel].area.first / 8 / 2;  in resample_expand()
94 		src_step = src_channels[channel].area.step / 8 / 2;  in resample_expand()
95 		dst_step = dst_channels[channel].area.step / 8 / 2;  in resample_expand()
98 		while (dst_frames1-- > 0) {  in resample_expand()
102 				if (src_frames1-- > 0) {  in resample_expand()
107 			val = S1 + ((S2 - S1) * (signed int)pos) / BITS;  in resample_expand()
108 			if (val < -32768)  in resample_expand()
109 				val = -32768;  in resample_expand()
114 			pos += data->pitch;  in resample_expand()
116 		rchannels->last_S1 = S1;  in resample_expand()
117 		rchannels->last_S2 = S2;  in resample_expand()
120 	data->pos = pos;  in resample_expand()
132 	unsigned int channel;  in resample_shrink()  local
135 	struct rate_priv *data = (struct rate_priv *)plugin->extra_data;  in resample_shrink()
136 	struct rate_channel *rchannels = data->channels;  in resample_shrink()
138 	for (channel = 0; channel < plugin->src_format.channels; ++channel) {  in resample_shrink()
139 		pos = data->pos;  in resample_shrink()
140 		S1 = rchannels->last_S1;  in resample_shrink()
141 		S2 = rchannels->last_S2;  in resample_shrink()
142 		if (!src_channels[channel].enabled) {  in resample_shrink()
143 			if (dst_channels[channel].wanted)  in resample_shrink()
144 				snd_pcm_area_silence(&dst_channels[channel].area, 0, dst_frames, plugin->dst_format.format);  in resample_shrink()
145 			dst_channels[channel].enabled = 0;  in resample_shrink()
148 		dst_channels[channel].enabled = 1;  in resample_shrink()
149 		src = (signed short *)src_channels[channel].area.addr +  in resample_shrink()
150 			src_channels[channel].area.first / 8 / 2;  in resample_shrink()
151 		dst = (signed short *)dst_channels[channel].area.addr +  in resample_shrink()
152 			dst_channels[channel].area.first / 8 / 2;  in resample_shrink()
153 		src_step = src_channels[channel].area.step / 8 / 2;  in resample_shrink()
154 		dst_step = dst_channels[channel].area.step / 8 / 2;  in resample_shrink()
159 			if (src_frames1-- > 0) {  in resample_shrink()
165 				val = S1 + ((S2 - S1) * (signed int)pos) / BITS;  in resample_shrink()
166 				if (val < -32768)  in resample_shrink()
167 					val = -32768;  in resample_shrink()
172 				dst_frames1--;  in resample_shrink()
174 			pos += data->pitch;  in resample_shrink()
176 		rchannels->last_S1 = S1;  in resample_shrink()
177 		rchannels->last_S2 = S2;  in resample_shrink()
180 	data->pos = pos;  in resample_shrink()
189 		return -ENXIO;  in rate_src_frames()
192 	data = (struct rate_priv *)plugin->extra_data;  in rate_src_frames()
193 	if (plugin->src_format.rate < plugin->dst_format.rate) {  in rate_src_frames()
194 		res = (((frames * data->pitch) + (BITS/2)) >> SHIFT);  in rate_src_frames()
196 		res = (((frames << SHIFT) + (data->pitch / 2)) / data->pitch);		  in rate_src_frames()
198 	if (data->old_src_frames > 0) {  in rate_src_frames()
199 		snd_pcm_sframes_t frames1 = frames, res1 = data->old_dst_frames;  in rate_src_frames()
200 		while (data->old_src_frames < frames1) {  in rate_src_frames()
204 		while (data->old_src_frames > frames1) {  in rate_src_frames()
208 		if (data->old_src_frames == frames1)  in rate_src_frames()
211 	data->old_src_frames = frames;  in rate_src_frames()
212 	data->old_dst_frames = res;  in rate_src_frames()
222 		return -ENXIO;  in rate_dst_frames()
225 	data = (struct rate_priv *)plugin->extra_data;  in rate_dst_frames()
226 	if (plugin->src_format.rate < plugin->dst_format.rate) {  in rate_dst_frames()
227 		res = (((frames << SHIFT) + (data->pitch / 2)) / data->pitch);  in rate_dst_frames()
229 		res = (((frames * data->pitch) + (BITS/2)) >> SHIFT);  in rate_dst_frames()
231 	if (data->old_dst_frames > 0) {  in rate_dst_frames()
232 		snd_pcm_sframes_t frames1 = frames, res1 = data->old_src_frames;  in rate_dst_frames()
233 		while (data->old_dst_frames < frames1) {  in rate_dst_frames()
237 		while (data->old_dst_frames > frames1) {  in rate_dst_frames()
241 		if (data->old_dst_frames == frames1)  in rate_dst_frames()
244 	data->old_dst_frames = frames;  in rate_dst_frames()
245 	data->old_src_frames = res;  in rate_dst_frames()
258 		return -ENXIO;  in rate_transfer()
263 		unsigned int channel;  in rate_transfer()  local
264 		for (channel = 0; channel < plugin->src_format.channels; channel++) {  in rate_transfer()
265 			if (snd_BUG_ON(src_channels[channel].area.first % 8 ||  in rate_transfer()
266 				       src_channels[channel].area.step % 8))  in rate_transfer()
267 				return -ENXIO;  in rate_transfer()
268 			if (snd_BUG_ON(dst_channels[channel].area.first % 8 ||  in rate_transfer()
269 				       dst_channels[channel].area.step % 8))  in rate_transfer()
270 				return -ENXIO;  in rate_transfer()
278 	data = (struct rate_priv *)plugin->extra_data;  in rate_transfer()
279 	data->func(plugin, src_channels, dst_channels, frames, dst_frames);  in rate_transfer()
288 		return -ENXIO;  in rate_action()
310 		return -ENXIO;  in snd_pcm_plugin_build_rate()
313 	if (snd_BUG_ON(src_format->channels != dst_format->channels))  in snd_pcm_plugin_build_rate()
314 		return -ENXIO;  in snd_pcm_plugin_build_rate()
315 	if (snd_BUG_ON(src_format->channels <= 0))  in snd_pcm_plugin_build_rate()
316 		return -ENXIO;  in snd_pcm_plugin_build_rate()
317 	if (snd_BUG_ON(src_format->format != SNDRV_PCM_FORMAT_S16))  in snd_pcm_plugin_build_rate()
318 		return -ENXIO;  in snd_pcm_plugin_build_rate()
319 	if (snd_BUG_ON(dst_format->format != SNDRV_PCM_FORMAT_S16))  in snd_pcm_plugin_build_rate()
320 		return -ENXIO;  in snd_pcm_plugin_build_rate()
321 	if (snd_BUG_ON(src_format->rate == dst_format->rate))  in snd_pcm_plugin_build_rate()
322 		return -ENXIO;  in snd_pcm_plugin_build_rate()
327 					       src_format->channels),  in snd_pcm_plugin_build_rate()
331 	data = (struct rate_priv *)plugin->extra_data;  in snd_pcm_plugin_build_rate()
332 	if (src_format->rate < dst_format->rate) {  in snd_pcm_plugin_build_rate()
333 		data->pitch = ((src_format->rate << SHIFT) + (dst_format->rate >> 1)) / dst_format->rate;  in snd_pcm_plugin_build_rate()
334 		data->func = resample_expand;  in snd_pcm_plugin_build_rate()
336 		data->pitch = ((dst_format->rate << SHIFT) + (src_format->rate >> 1)) / src_format->rate;  in snd_pcm_plugin_build_rate()
337 		data->func = resample_shrink;  in snd_pcm_plugin_build_rate()
339 	data->pos = 0;  in snd_pcm_plugin_build_rate()
341 	data->old_src_frames = data->old_dst_frames = 0;  in snd_pcm_plugin_build_rate()
342 	plugin->transfer = rate_transfer;  in snd_pcm_plugin_build_rate()
343 	plugin->src_frames = rate_src_frames;  in snd_pcm_plugin_build_rate()
344 	plugin->dst_frames = rate_dst_frames;  in snd_pcm_plugin_build_rate()
345 	plugin->action = rate_action;  in snd_pcm_plugin_build_rate()