playback.cpp

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#ifdef HAVE_CONFIG_H
#include "config.h"
#include "config_unix.h"
#include "config_win32.h"
#endif /* HAVE_CONFIG_H */
 
#include <memory>
#include <string_view>
 
#include "debug.h"
#include "module.h"
#include "audio/audio_filter.h"
#include "audio/types.h"
#include "audio/audio_playback.h" 
#include "lib_common.h"
#include "utils/string_view_utils.hpp"
#include "utils/misc.h"
 
namespace{
struct Playback_dev_deleter{ void operator()(state_audio_playback *p){ audio_playback_done(p); } };
using Playback_dev_uniq = std::unique_ptr<state_audio_playback, Playback_dev_deleter>;
}
 
struct state_playback{
        state_playback(struct module *mod) : mod(MODULE_CLASS_DATA, mod, this) {  }
 
        module_raii mod;
 
        int bps = 0;
        int ch_count = 0;
        int sample_rate = 0;
 
        Playback_dev_uniq playback_dev;
 
};
 
static void usage(){
        printf("Plays audio using an UltraGrid playback device:\n\n");
        printf("playback usage:\n");
        printf("\tplayback:<playback dev>:<dev config>\n\n");
}
 
static af_result_code parse_cfg(state_playback *s, std::string_view cfg){
        auto tok = tokenize(cfg, ':');
        if(tok.empty() || tok == "help"){
                usage();
                return AF_HELP_SHOWN;
        } 
 
        auto dev = std::string(tok);
        auto dev_cfg = std::string(tokenize(cfg, ':'));
 
        int ret = audio_playback_init(dev.c_str(), dev_cfg.c_str(), out_ptr(s->playback_dev));
 
        return ret == 0 ? AF_OK : AF_FAILURE;
}
 
static af_result_code init(struct module *parent, const char *cfg, void **state){
        auto s = std::make_unique<state_playback>(parent);
 
        auto ret = parse_cfg(s.get(), cfg);
        if(ret == AF_OK)
                *state = s.release();
 
        return ret;
};
 
static af_result_code configure(void *state,
                        int in_bps, int in_ch_count, int in_sample_rate)
{
        auto s = static_cast<state_playback *>(state);
 
        s->bps = in_bps;
        s->ch_count = in_ch_count;
        s->sample_rate = in_sample_rate;
 
        if (audio_playback_reconfigure(s->playback_dev.get(), s->bps * 8,
                                s->ch_count,
                                s->sample_rate) != TRUE) {
                return AF_FAILURE;
        }
 
        return AF_OK;
}
 
static void done(void *state){
        auto s = static_cast<state_playback *>(state);
 
        delete s;
}
 
static void get_configured(void *state,
                        int *bps, int *ch_count, int *sample_rate)
{
        auto s = static_cast<state_playback *>(state);
 
        if(bps) *bps = s->bps;
        if(ch_count) *ch_count = s->ch_count;
        if(sample_rate) *sample_rate = s->sample_rate;
}
 
static af_result_code filter(void *state, struct audio_frame **frame){
        auto s = static_cast<state_playback *>(state);
 
        struct message *msg;
        while ((msg = check_message(s->mod.get()))) {
                const char *text = ((msg_universal *) msg)->text;
                if(parse_cfg(s, text) != AF_OK){
                        free_message(msg, new_response(RESPONSE_BAD_REQUEST, nullptr));
                        continue;
                }
 
                free_message(msg, new_response(RESPONSE_OK, nullptr));
        }
 
        auto f = *frame;
 
        if(f->bps != s->bps || f->ch_count != s->ch_count || f->sample_rate != s->sample_rate){
                if(configure(state, f->bps, f->ch_count, f->sample_rate) != AF_OK){
                        return AF_MISCONFIGURED;
                }
        }
 
        audio_playback_put_frame(s->playback_dev.get(), f);
 
        return AF_OK;
}
 
static const struct audio_filter_info audio_filter_playback = {
        .name = "playback",
        .init = init,
        .done = done,
        .configure = configure,
        .get_configured_in = get_configured,
        .get_configured_out = get_configured,
        .filter = filter,
};
 
REGISTER_MODULE(playback, &audio_filter_playback, LIBRARY_CLASS_AUDIO_FILTER, AUDIO_FILTER_ABI_VERSION);