pcm_plugin.c

优龙2410linux2.6.8内核源代码

        	err = snd_pcm_plugin_build_rate(plug,
        					&srcformat, &tmpformat,
						&plugin);
		pdprintf("rate down resampling: src=%i, dst=%i returns %i\n", srcformat.rate, tmpformat.rate, err);
		if (err < 0) {
			snd_pcm_plugin_free(plugin);
			return err;
		}      					    
		err = snd_pcm_plugin_append(plugin);
		if (err < 0) {
			snd_pcm_plugin_free(plugin);
			return err;
		}
		srcformat = tmpformat;
		src_access = dst_access;
        }

	/* channels extension  */
	if (srcformat.channels < dstformat.channels) {
		int sv = srcformat.channels;
		int dv = dstformat.channels;
		route_ttable_entry_t *ttable = snd_kcalloc(dv * sv * sizeof(*ttable), GFP_KERNEL);
		if (ttable == NULL)
			return -ENOMEM;
#if 0
		{
			int v;
			for (v = 0; v < sv; ++v)
				ttable[v * sv + v] = FULL;
		}
#else
		{
			/* Playback is spreaded on all channels */
			int vd, vs;
			for (vd = 0, vs = 0; vd < dv; ++vd) {
				ttable[vd * sv + vs] = FULL;
				vs++;
				if (vs == sv)
					vs = 0;
			}
		}
#endif
		tmpformat.channels = dstformat.channels;
		if (snd_pcm_format_linear(dstformat.format))
			tmpformat.format = dstformat.format;
		err = snd_pcm_plugin_build_route(plug,
						 &srcformat, &tmpformat,
						 ttable, &plugin);
		kfree(ttable);
		pdprintf("channels extension: src=%i, dst=%i returns %i\n", srcformat.channels, tmpformat.channels, err);
		if (err < 0) {
			snd_pcm_plugin_free(plugin);
			return err;
		}      					    
		err = snd_pcm_plugin_append(plugin);
		if (err < 0) {
			snd_pcm_plugin_free(plugin);
			return err;
		}
		srcformat = tmpformat;
		src_access = dst_access;
	}

	/* format change */
	if (srcformat.format != dstformat.format) {
		tmpformat.format = dstformat.format;
		if (tmpformat.format == SNDRV_PCM_FORMAT_MU_LAW) {
			err = snd_pcm_plugin_build_mulaw(plug,
							 &srcformat, &tmpformat,
							 &plugin);
		}
		else if (snd_pcm_format_linear(srcformat.format) &&
			 snd_pcm_format_linear(tmpformat.format)) {
			err = snd_pcm_plugin_build_linear(plug,
							  &srcformat, &tmpformat,
							  &plugin);
		}
		else
			return -EINVAL;
		pdprintf("format change: src=%i, dst=%i returns %i\n", srcformat.format, tmpformat.format, err);
		if (err < 0)
			return err;
		err = snd_pcm_plugin_append(plugin);
		if (err < 0) {
			snd_pcm_plugin_free(plugin);
			return err;
		}
		srcformat = tmpformat;
		src_access = dst_access;
	}

	/* de-interleave */
	if (src_access != dst_access) {
		err = snd_pcm_plugin_build_copy(plug,
						&srcformat,
						&tmpformat,
						&plugin);
		pdprintf("interleave change (copy: returns %i)\n", err);
		if (err < 0)
			return err;
		err = snd_pcm_plugin_append(plugin);
		if (err < 0) {
			snd_pcm_plugin_free(plugin);
			return err;
		}
	}

	return 0;
}

snd_pcm_sframes_t snd_pcm_plug_client_channels_buf(snd_pcm_plug_t *plug,
					 char *buf,
					 snd_pcm_uframes_t count,
					 snd_pcm_plugin_channel_t **channels)
{
	snd_pcm_plugin_t *plugin;
	snd_pcm_plugin_channel_t *v;
	snd_pcm_plugin_format_t *format;
	int width, nchannels, channel;
	int stream = snd_pcm_plug_stream(plug);

	snd_assert(buf != NULL, return -ENXIO);
	if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
		plugin = snd_pcm_plug_first(plug);
		format = &plugin->src_format;
	} else {
		plugin = snd_pcm_plug_last(plug);
		format = &plugin->dst_format;
	}
	v = plugin->buf_channels;
	*channels = v;
	if ((width = snd_pcm_format_physical_width(format->format)) < 0)
		return width;
	nchannels = format->channels;
	snd_assert(plugin->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED || format->channels <= 1, return -ENXIO);
	for (channel = 0; channel < nchannels; channel++, v++) {
		v->frames = count;
		v->enabled = 1;
		v->wanted = (stream == SNDRV_PCM_STREAM_CAPTURE);
		v->area.addr = buf;
		v->area.first = channel * width;
		v->area.step = nchannels * width;
	}
	return count;
}

int snd_pcm_plug_playback_channels_mask(snd_pcm_plug_t *plug,
					bitset_t *client_vmask)
{
	snd_pcm_plugin_t *plugin = snd_pcm_plug_last(plug);
	if (plugin == NULL) {
		return 0;
	} else {
		int schannels = plugin->dst_format.channels;
		bitset_t bs[bitset_size(schannels)];
		bitset_t *srcmask;
		bitset_t *dstmask = bs;
		int err;
		bitset_one(dstmask, schannels);
		if (plugin == NULL) {
			bitset_and(client_vmask, dstmask, schannels);
			return 0;
		}
		while (1) {
			err = plugin->src_channels_mask(plugin, dstmask, &srcmask);
			if (err < 0)
				return err;
			dstmask = srcmask;
			if (plugin->prev == NULL)
				break;
			plugin = plugin->prev;
		}
		bitset_and(client_vmask, dstmask, plugin->src_format.channels);
		return 0;
	}
}

int snd_pcm_plug_capture_channels_mask(snd_pcm_plug_t *plug,
				       bitset_t *client_vmask)
{
	snd_pcm_plugin_t *plugin = snd_pcm_plug_first(plug);
	if (plugin == NULL) {
		return 0;
	} else {
		int schannels = plugin->src_format.channels;
		bitset_t bs[bitset_size(schannels)];
		bitset_t *srcmask = bs;
		bitset_t *dstmask;
		int err;
		bitset_one(srcmask, schannels);
		while (1) {
			err = plugin->dst_channels_mask(plugin, srcmask, &dstmask);
			if (err < 0)
				return err;
			srcmask = dstmask;
			if (plugin->next == NULL)
				break;
			plugin = plugin->next;
		}
		bitset_and(client_vmask, srcmask, plugin->dst_format.channels);
		return 0;
	}
}

static int snd_pcm_plug_playback_disable_useless_channels(snd_pcm_plug_t *plug,
							  snd_pcm_plugin_channel_t *src_channels)
{
	snd_pcm_plugin_t *plugin = snd_pcm_plug_first(plug);
	unsigned int nchannels = plugin->src_format.channels;
	bitset_t bs[bitset_size(nchannels)];
	bitset_t *srcmask = bs;
	int err;
	unsigned int channel;
	for (channel = 0; channel < nchannels; channel++) {
		if (src_channels[channel].enabled)
			bitset_set(srcmask, channel);
		else
			bitset_reset(srcmask, channel);
	}
	err = snd_pcm_plug_playback_channels_mask(plug, srcmask);
	if (err < 0)
		return err;
	for (channel = 0; channel < nchannels; channel++) {
		if (!bitset_get(srcmask, channel))
			src_channels[channel].enabled = 0;
	}
	return 0;
}

static int snd_pcm_plug_capture_disable_useless_channels(snd_pcm_plug_t *plug,
							 snd_pcm_plugin_channel_t *src_channels,
							 snd_pcm_plugin_channel_t *client_channels)
{
	snd_pcm_plugin_t *plugin = snd_pcm_plug_last(plug);
	unsigned int nchannels = plugin->dst_format.channels;
	bitset_t bs[bitset_size(nchannels)];
	bitset_t *dstmask = bs;
	bitset_t *srcmask;
	int err;
	unsigned int channel;
	for (channel = 0; channel < nchannels; channel++) {
		if (client_channels[channel].enabled)
			bitset_set(dstmask, channel);
		else
			bitset_reset(dstmask, channel);
	}
	while (plugin) {
		err = plugin->src_channels_mask(plugin, dstmask, &srcmask);
		if (err < 0)
			return err;
		dstmask = srcmask;
		plugin = plugin->prev;
	}
	plugin = snd_pcm_plug_first(plug);
	nchannels = plugin->src_format.channels;
	for (channel = 0; channel < nchannels; channel++) {
		if (!bitset_get(dstmask, channel))
			src_channels[channel].enabled = 0;
	}
	return 0;
}

snd_pcm_sframes_t snd_pcm_plug_write_transfer(snd_pcm_plug_t *plug, snd_pcm_plugin_channel_t *src_channels, snd_pcm_uframes_t size)
{
	snd_pcm_plugin_t *plugin, *next;
	snd_pcm_plugin_channel_t *dst_channels;
	int err;
	snd_pcm_sframes_t frames = size;

	if ((err = snd_pcm_plug_playback_disable_useless_channels(plug, src_channels)) < 0)
		return err;
	
	plugin = snd_pcm_plug_first(plug);
	while (plugin && frames > 0) {
		if ((next = plugin->next) != NULL) {
			snd_pcm_sframes_t frames1 = frames;
			if (plugin->dst_frames)
				frames1 = plugin->dst_frames(plugin, frames);
			if ((err = next->client_channels(next, frames1, &dst_channels)) < 0) {
				return err;
			}
			if (err != frames1) {
				frames = err;
				if (plugin->src_frames)
					frames = plugin->src_frames(plugin, frames1);
			}
		} else
			dst_channels = NULL;
		pdprintf("write plugin: %s, %li\n", plugin->name, frames);
		if ((frames = plugin->transfer(plugin, src_channels, dst_channels, frames)) < 0)
			return frames;
		src_channels = dst_channels;
		plugin = next;
	}
	return snd_pcm_plug_client_size(plug, frames);
}

snd_pcm_sframes_t snd_pcm_plug_read_transfer(snd_pcm_plug_t *plug, snd_pcm_plugin_channel_t *dst_channels_final, snd_pcm_uframes_t size)
{
	snd_pcm_plugin_t *plugin, *next;
	snd_pcm_plugin_channel_t *src_channels, *dst_channels;
	snd_pcm_sframes_t frames = size;
	int err;

	frames = snd_pcm_plug_slave_size(plug, frames);
	if (frames < 0)
		return frames;

	src_channels = NULL;
	plugin = snd_pcm_plug_first(plug);
	while (plugin && frames > 0) {
		if ((next = plugin->next) != NULL) {
			if ((err = plugin->client_channels(plugin, frames, &dst_channels)) < 0) {
				return err;
			}
			frames = err;
			if (!plugin->prev) {
				if ((err = snd_pcm_plug_capture_disable_useless_channels(plug, dst_channels, dst_channels_final)) < 0)
					return err;
			}
		} else {
			dst_channels = dst_channels_final;
		}
		pdprintf("read plugin: %s, %li\n", plugin->name, frames);
		if ((frames = plugin->transfer(plugin, src_channels, dst_channels, frames)) < 0)
			return frames;
		plugin = next;
		src_channels = dst_channels;
	}
	return frames;
}

int snd_pcm_area_silence(const snd_pcm_channel_area_t *dst_area, size_t dst_offset,
			 size_t samples, int format)
{
	/* FIXME: sub byte resolution and odd dst_offset */
	char *dst;
	unsigned int dst_step;
	int width;
	u_int64_t silence;
	if (!dst_area->addr)
		return 0;
	dst = dst_area->addr + (dst_area->first + dst_area->step * dst_offset) / 8;
	width = snd_pcm_format_physical_width(format);
	silence = snd_pcm_format_silence_64(format);
	if (dst_area->step == (unsigned int) width) {
		size_t dwords = samples * width / 64;
		u_int64_t *dst64 = (u_int64_t *)dst;

		samples -= dwords * 64 / width;
		while (dwords-- > 0)
			*dst64++ = silence;
		if (samples == 0)
			return 0;
		dst = (char *)dst64;
	}
	dst_step = dst_area->step / 8;
	switch (width) {
	case 4: {
		u_int8_t s0 = silence & 0xf0;
		u_int8_t s1 = silence & 0x0f;
		int dstbit = dst_area->first % 8;
		int dstbit_step = dst_area->step % 8;
		while (samples-- > 0) {
			if (dstbit) {
				*dst &= 0xf0;
				*dst |= s1;
			} else {
				*dst &= 0x0f;
				*dst |= s0;
			}
			dst += dst_step;
			dstbit += dstbit_step;
			if (dstbit == 8) {
				dst++;
				dstbit = 0;
			}
		}
		break;
	}
	case 8: {
		u_int8_t sil = silence;
		while (samples-- > 0) {
			*dst = sil;
			dst += dst_step;
		}
		break;
	}
	case 16: {
		u_int16_t sil = silence;
		while (samples-- > 0) {
			*(u_int16_t*)dst = sil;
			dst += dst_step;
		}
		break;
	}
	case 32: {
		u_int32_t sil = silence;
		while (samples-- > 0) {
			*(u_int32_t*)dst = sil;
			dst += dst_step;
		}
		break;
	}
	case 64: {
		while (samples-- > 0) {
			*(u_int64_t*)dst = silence;
			dst += dst_step;
		}
		break;
	}
	default:
		snd_BUG();
	}
	return 0;
}

int snd_pcm_area_copy(const snd_pcm_channel_area_t *src_area, size_t src_offset,
		      const snd_pcm_channel_area_t *dst_area, size_t dst_offset,
		      size_t samples, int format)
{
	/* FIXME: sub byte resolution and odd dst_offset */
	char *src, *dst;
	int width;
	int src_step, dst_step;
	src = src_area->addr + (src_area->first + src_area->step * src_offset) / 8;
	if (!src_area->addr)
		return snd_pcm_area_silence(dst_area, dst_offset, samples, format);
	dst = dst_area->addr + (dst_area->first + dst_area->step * dst_offset) / 8;
	if (!dst_area->addr)
		return 0;
	width = snd_pcm_format_physical_width(format);
	if (src_area->step == (unsigned int) width &&
	    dst_area->step == (unsigned int) width) {
		size_t bytes = samples * width / 8;
		samples -= bytes * 8 / width;
		memcpy(dst, src, bytes);
		if (samples == 0)
			return 0;
	}
	src_step = src_area->step / 8;
	dst_step = dst_area->step / 8;
	switch (width) {
	case 4: {
		int srcbit = src_area->first % 8;
		int srcbit_step = src_area->step % 8;
		int dstbit = dst_area->first % 8;
		int dstbit_step = dst_area->step % 8;
		while (samples-- > 0) {
			unsigned char srcval;
			if (srcbit)
				srcval = *src & 0x0f;
			else
				srcval = *src & 0xf0;
			if (dstbit)
				*dst &= 0xf0;
			else
				*dst &= 0x0f;
			*dst |= srcval;
			src += src_step;
			srcbit += srcbit_step;
			if (srcbit == 8) {
				src++;
				srcbit = 0;
			}
			dst += dst_step;
			dstbit += dstbit_step;
			if (dstbit == 8) {
				dst++;
				dstbit = 0;
			}
		}
		break;
	}
	case 8: {
		while (samples-- > 0) {
			*dst = *src;
			src += src_step;
			dst += dst_step;
		}
		break;
	}
	case 16: {
		while (samples-- > 0) {
			*(u_int16_t*)dst = *(u_int16_t*)src;
			src += src_step;
			dst += dst_step;
		}
		break;
	}
	case 32: {
		while (samples-- > 0) {
			*(u_int32_t*)dst = *(u_int32_t*)src;
			src += src_step;
			dst += dst_step;
		}
		break;
	}
	case 64: {
		while (samples-- > 0) {
			*(u_int64_t*)dst = *(u_int64_t*)src;
			src += src_step;
			dst += dst_step;
		}
		break;
	}
	default:
		snd_BUG();
	}
	return 0;
}