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#include <cassert>
#include <cstdint>
#include <dlfcn.h>
#include <stdlib.h>
#ifndef _CUBEB_MEDIA_LIBRARY_H_
#define _CUBEB_MEDIA_LIBRARY_H_
typedef int32_t (*get_output_latency_ptr)(uint32_t * latency, int stream_type);
struct media_lib {
void * libmedia;
get_output_latency_ptr get_output_latency;
};
typedef struct media_lib media_lib;
media_lib *
cubeb_load_media_library()
{
media_lib ml = {};
ml.libmedia = dlopen("libmedia.so", RTLD_LAZY);
if (!ml.libmedia) {
return nullptr;
}
// Get the latency, in ms, from AudioFlinger. First, try the most recent
// signature. status_t AudioSystem::getOutputLatency(uint32_t* latency,
// audio_stream_type_t streamType)
ml.get_output_latency = (get_output_latency_ptr)dlsym(
ml.libmedia,
"_ZN7android11AudioSystem16getOutputLatencyEPj19audio_stream_type_t");
if (!ml.get_output_latency) {
// In case of failure, try the signature from legacy version.
// status_t AudioSystem::getOutputLatency(uint32_t* latency, int streamType)
ml.get_output_latency = (get_output_latency_ptr)dlsym(
ml.libmedia, "_ZN7android11AudioSystem16getOutputLatencyEPji");
if (!ml.get_output_latency) {
return nullptr;
}
}
media_lib * rv = nullptr;
rv = (media_lib *)calloc(1, sizeof(media_lib));
assert(rv);
*rv = ml;
return rv;
}
void
cubeb_close_media_library(media_lib * ml)
{
dlclose(ml->libmedia);
ml->libmedia = NULL;
ml->get_output_latency = NULL;
free(ml);
}
uint32_t
cubeb_get_output_latency_from_media_library(media_lib * ml)
{
uint32_t latency = 0;
const int audio_stream_type_music = 3;
int32_t r = ml->get_output_latency(&latency, audio_stream_type_music);
if (r) {
return 0;
}
return latency;
}
#endif // _CUBEB_MEDIA_LIBRARY_H_