【VC开源代码栏目提醒】:网学会员为广大网友收集整理了,audio_sdl.cpp,希望对大家有所帮助!
/*
* The contents of this file are subject to the Mozilla Public
* License Version 1.1 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS
* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
* implied. See the License for the specific language governing
* rights and limitations under the License.
*
* The Original Code is MPEG4IP.
*
* The Initial Developer of the Original Code is Cisco Systems Inc.
* Portions created by Cisco Systems Inc. are
* Copyright (C) Cisco Systems Inc. 2000, 2001. All Rights Reserved.
*
* Contributor(s):
* Bill May wmay@cisco.com
*/
/*
* audio.cpp provides an interface (CAudioSync) between the codec and
* the SDL audio APIs.
*/
#include <stdlib.h>
#include <string.h>
#include "player_session.h"
#include "audio_sdl.h"
#include "player_util.h"
#include <SDL_thread.h>
//#define DEBUG_SYNC 1
//#define DEBUG_AUDIO_FILL 1
//#define DEBUG_DELAY 1
#ifdef _WIN32
DEFINE_MESSAGE_MACRO(audio_message, "audiosync")
#else
#define audio_message(loglevel, fmt...) message(loglevel, "audiosync", fmt)
#endif
/*
* c routine to call into the AudioSync class callback
*/
static void c_audio_callback (void *userdata, Uint8 *stream, int len)
{
CSDLAudioSync *a = (CSDLAudioSync *)userdata;
a->audio_callback(stream, len);
}
/*
* Create an CSDLAudioSync for a session. Don't alloc any buffers until
* config is called by codec
*/
CSDLAudioSync::CSDLAudioSync (CPlayerSession *psptr, int volume) :
CAudioSync(psptr)
{
SDL_Init(SDL_INIT_AUDIO | SDL_INIT_NOPARACHUTE);
m_fill_index = m_play_index = 0;
for (int ix = 0; ix < DECODE_BUFFERS_MAX; ix++) {
m_buffer_filled[ix] = 0;
m_sample_buffer[ix] = NULL;
}
m_buffer_size = 0;
m_config_set = 0;
m_audio_initialized = 0;
m_audio_paused = 1;
m_resync_required = 1;
m_dont_fill = 0;
m_consec_no_buffers = 0;
//SDL_Init(SDL_INIT_AUDIO);
m_audio_waiting_buffer = 0;
m_audio_waiting = SDL_CreateSemaphore(0); //NULL; // will be set by decode thread
m_skipped_buffers = 0;
m_didnt_fill_buffers = 0;
m_play_time = 0 ;
m_buffer_latency = 0;
m_volume = (volume * SDL_MIX_MAXVOLUME)/100;
m_first_time = 1;
m_first_filled = 1;
m_buffer_offset_on = 0;
m_buffer_ts = 0;
m_load_audio_do_next_resync = 0;
}
/*
* Close out audio sync - stop and disconnect from SDL
*/
CSDLAudioSync::~CSDLAudioSync (void)
{
SDL_PauseAudio(1);
SDL_CloseAudio();
for (int ix = 0; ix < DECODE_BUFFERS_MAX; ix++) {
if (m_sample_buffer[ix] != NULL)
free(m_sample_buffer[ix]);
m_sample_buffer[ix] = NULL;
}
audio_message(LOG_NOTICE,
"Audio sync skipped %u buffers",
m_skipped_buffers);
audio_message(LOG_NOTICE, "didn't fill %u buffers", m_didnt_fill_buffers);
}
/*
* codec api - set up information about the stream
*/
void CSDLAudioSync::set_config (int freq,
int channels,
int format,
uint32_t sample_size)
{
if (m_config_set != 0)
return;
if (format == AUDIO_U8 || format == AUDIO_S8)
m_bytes_per_sample = 1;
else
m_bytes_per_sample = 2;
if (sample_size == 0) {
int temp;
temp = freq;
while ((temp & 0x1) == 0) temp >>= 1;
sample_size = temp;
}
m_buffer_size = channels * sample_size * m_bytes_per_sample;
for (int ix = 0; ix < DECODE_BUFFERS_MAX; ix++) {
m_buffer_filled[ix] = 0;
// I'm not sure where the 2 * comes in... Check this out
m_sample_buffer[ix] =
(uint8_t *)malloc(2 * m_buffer_size);
}
m_freq = freq;
m_channels = channels;
m_format = format;
m_config_set = 1;
m_msec_per_frame = sample_size * 1000 / m_freq;
audio_message(LOG_DEBUG, "buffer size %d msec per frame %d",
m_buffer_size, m_msec_per_frame);
};
/*
* Codec api - get_audio_buffer - will wait if there are no available
* buffers
*/
uint8_t *CSDLAudioSync::get_audio_buffer (void)
{
int ret;
int locked = 0;
if (m_dont_fill == 1) {
#ifdef DEBUG_AUDIO_FILL
audio_message(LOG_DEBUG, "first dont fill");
#endif
return (NULL);
}
if (m_audio_initialized != 0) {
locked = 1;
SDL_LockAudio();
}
ret = m_buffer_filled[m_fill_index];
if (locked)
SDL_UnlockAudio();
if (ret == 1) {
m_audio_waiting_buffer = 1;
SDL_SemWait(m_audio_waiting);
m_audio_waiting_buffer = 0;
if (m_dont_fill != 0) {
#ifdef DEBUG_AUDIO_FILL
audio_message(LOG_DEBUG, "2nd don't fill");
#endif
return (NULL);
}
locked = 0;
if (m_audio_initialized != 0) {
SDL_LockAudio();
locked = 1;
}
ret = m_buffer_filled[m_fill_index];
if (locked)
SDL_UnlockAudio();
if (ret == 1) {
#ifdef DEBUG_AUDIO_FIL