mirror of
https://github.com/alsa-project/alsa-lib.git
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81 lines
2.3 KiB
C
81 lines
2.3 KiB
C
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/*
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* PCM Block Plug-In Interface
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* Copyright (c) 1999 by Jaroslav Kysela <perex@suse.cz>
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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., 675 Mass Ave, Cambridge, MA 02139, USA.
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*
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <string.h>
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#include <errno.h>
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#include "../pcm_local.h"
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/*
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* Basic block plugin
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*/
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struct block_private_data {
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snd_pcm_t *pcm;
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int channel;
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};
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static ssize_t block_transfer(snd_pcm_plugin_t *plugin,
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char *src_ptr, size_t src_size,
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char *dst_ptr, size_t dst_size)
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{
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struct block_private_data *data;
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if (plugin == NULL || dst_ptr == NULL || dst_size <= 0)
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return -EINVAL;
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data = (struct block_private_data *)snd_pcm_plugin_extra_data(plugin);
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if (data == NULL)
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return -EINVAL;
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if (data->channel == SND_PCM_CHANNEL_PLAYBACK) {
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return snd_pcm_write(data->pcm, dst_ptr, dst_size);
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} else if (data->channel == SND_PCM_CHANNEL_CAPTURE) {
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return snd_pcm_read(data->pcm, dst_ptr, dst_size);
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} else {
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return -EINVAL;
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}
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}
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int snd_pcm_plugin_build_block(snd_pcm_t *pcm, int channel, snd_pcm_plugin_t **r_plugin)
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{
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struct block_private_data *data;
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snd_pcm_plugin_t *plugin;
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if (r_plugin == NULL)
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return -EINVAL;
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*r_plugin = NULL;
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if (!pcm || channel < 0 || channel > 1)
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return -EINVAL;
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plugin = snd_pcm_plugin_build(channel == SND_PCM_CHANNEL_PLAYBACK ?
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"I/O block playback" :
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"I/O block capture",
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sizeof(struct block_private_data));
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if (plugin == NULL)
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return -ENOMEM;
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data = (struct block_private_data *)snd_pcm_plugin_extra_data(plugin);
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data->pcm = pcm;
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data->channel = channel;
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plugin->transfer = block_transfer;
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*r_plugin = plugin;
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return 0;
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}
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