先来看看sdl播放pcm的简单例子，比起Android的AudioTrack和直接用tinyalsa的pcm_open,pcm_write,pcm_close方式有些抽象。编译命令：
gcc -o mypcm mypcm.c -I /usr/local/include/SDL2/ -lSDL2
#include<stdio.h>
#include<SDL.h>
#include <pthread.h>
#define BUFFER_SIZE 81920
#define ID_RIFF 0x46464952
#define ID_WAVE 0x45564157
#define ID_FMT 0x20746d66
#define ID_DATA 0x61746164
struct riff_wave_header {
uint32_t riff_id;
uint32_t riff_sz;
uint32_t wave_id;
};
struct chunk_header {
uint32_t id;
uint32_t sz;
};
struct chunk_fmt {
uint16_t audio_format;
uint16_t num_channels;
uint32_t sample_rate;
uint32_t byte_rate;
uint16_t block_align;
uint16_t bits_per_sample;
};
static Uint8 *data_buf = NULL;
static Uint8 *consume_pos = NULL;
static uint32_t data_len = 0;
void consume_audio_data(void *udata, Uint8 *stream, int len){
if(data_len == 0){
printf("consume_audio_data data_len == 0 return \n");
return;
}
SDL_memset(stream, 0, len);
len = (len < data_len) ? len : data_len;
SDL_MixAudio(stream, consume_pos, len, SDL_MIX_MAXVOLUME);
consume_pos = len;
}
int main(int argc, char *argv[]){
FILE *wavFd = NULL;
SDL_AudioSpec spec;
int more_chunks = 1;
struct riff_wave_header riff_wave_header;
struct chunk_header chunk_header;
struct chunk_fmt chunk_fmt;
if(argc < 2) {
printf("\n\n/Usage:./main xxxx.wav/\n");
}
//初始化SDL
if(SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_TIMER)){
printf("Could not initialize SDL - %s\n", SDL_GetError());
return -1;
}
//打开wav文件
wavFd = fopen(argv[1], "rb");
if(!wavFd){
fprintf(stderr, "Failed to open pcm file!\n");
goto __FAIL;
}
//读取wav文件头
fread(&riff_wave_header, sizeof(riff_wave_header), 1, wavFd);
if ((riff_wave_header.riff_id != ID_RIFF) ||
(riff_wave_header.wave_id != ID_WAVE)) {
fprintf(stderr, "Error: '%s' is not a riff/wave file\n", argv[1]);
fclose(wavFd);
goto __FAIL;
}
do {
fread(&chunk_header, sizeof(chunk_header), 1, wavFd);
switch (chunk_header.id) {
case ID_FMT:
fread(&chunk_fmt, sizeof(chunk_fmt), 1, wavFd);
if (chunk_header.sz > sizeof(chunk_fmt))
fseek(wavFd, chunk_header.sz - sizeof(chunk_fmt), SEEK_CUR);
break;
case ID_DATA:
more_chunks = 0;
chunk_header.sz = le32toh(chunk_header.sz);
break;
default:
fseek(wavFd, chunk_header.sz, SEEK_CUR);
}
} while (more_chunks);
//分配buffer
data_buf = (Uint8*)malloc(BUFFER_SIZE);
if(!data_buf){
printf("malloc data_buf fail!\n");
goto __FAIL;
}
//填充结构体各字段
spec.freq = chunk_fmt.sample_rate;
switch (chunk_fmt.bits_per_sample){
case 16:
spec.format = AUDIO_S16SYS;//AUDIO_U16SYS;
break;
case 32:
spec.format = AUDIO_S32SYS;
break;
default:
printf("not support this format\n");
goto __FAIL;
}
spec.channels = chunk_fmt.num_channels;
spec.silence = 0;
spec.samples = 2048;
spec.callback = consume_audio_data;//回调函数由SDL内部线程调用
spec.userdata = NULL;
printf("spec.channels=%d,spec.freq=%d, chunk_fmt.bits_per_sample=%d\n", spec.channels, spec.freq, chunk_fmt.bits_per_sample);
//打开sdl audio设备
if(SDL_OpenAudio(&spec, NULL)){
fprintf(stderr, "Failed to open audio device, %s\n", SDL_GetError());
goto __FAIL;
}
//0:播放，1:暂停
SDL_PauseAudio(0);
do{
//读取pcm数据
data_len = fread(data_buf, 1, BUFFER_SIZE, wavFd);
// fprintf(stderr, "fread data_len = %d\n", data_len);
consume_pos = data_buf;
//sdl内部线程还没有播放完数据，这里延时等待
while(consume_pos < (data_buf data_len)) {
SDL_Delay(1);
}
}while(data_len !=0);
SDL_CloseAudio();
__FAIL:
if(data_buf){
free(data_buf);
}
if(wavFd){
fclose(wavFd);
}
SDL_Quit();
}
可以自己用ffmpeg命令把mp4转成yuv。
ffmpeg -i U1.mp4 -ss 00:00:20 -t 10 -s 320x240 -pix_fmt yuv420p U1_320X240_yuv420p.yuv
编译命令：
gcc -o myplayer myplayer .c -I /usr/local/include/SDL2/ -lSDL2
执行：./myplayer ../../U1_320X240_yuv420p.yuv
#include <stdio.h>
#include <string.h>
#include <SDL.h>
//event message
#define REFRESH_EVENT (SDL_USEREVENT 1)
#define QUIT_EVENT (SDL_USEREVENT 2)
int thread_exit = 0;
int refresh_video(void *udata){
thread_exit=0;
while (!thread_exit) {
SDL_Event event;
event.type = REFRESH_EVENT;
SDL_PushEvent(&event);
//40ms就是25帧
SDL_Delay(40);
}
thread_exit=0;
//push quit event
SDL_Event event;
event.type = QUIT_EVENT;
SDL_PushEvent(&event);
return 0;
}
int main(int argc, char* argv[])
{
FILE *file_fd = NULL;
SDL_Event event;
SDL_Rect rect;
Uint32 pixformat = 0;
Uint8 *frame_buf = NULL;
SDL_Window *win = NULL;
SDL_Renderer *renderer = NULL;
SDL_Texture *texture = NULL;
SDL_Thread *refresh_thread = NULL;
int video_width = 320, video_height = 240;
//yuv每个像素使用1.5byte
unsigned int yuv_frame_size = video_width * video_height * 12 / 8;
frame_buf = malloc(yuv_frame_size);
memset(frame_buf, 0, yuv_frame_size);
//initialize SDL
if(SDL_Init(SDL_INIT_VIDEO)) {
fprintf( stderr, "Could not initialize SDL - %s\n", SDL_GetError());
return -1;
}
//creat window from SDL
win = SDL_CreateWindow("YUV Player",
SDL_WINDOWPOS_UNDEFINED,
SDL_WINDOWPOS_UNDEFINED,
video_width, video_height,
SDL_WINDOW_OPENGL);
if(!win) {
fprintf(stderr, "Failed to create window, %s\n",SDL_GetError());
goto __FAIL;
}
renderer = SDL_CreateRenderer(win, -1, 0);
//IYUV: Y U V (3 planes)
//YV12: Y V U (3 planes)
pixformat= SDL_PIXELFORMAT_IYUV;
//create texture for render
texture = SDL_CreateTexture(renderer,
pixformat,
SDL_TEXTUREACCESS_STREAMING,
video_width,
video_height);
//open yuv file
file_fd = fopen(argv[1], "rb");
if( !file_fd ){
fprintf(stderr, "Failed to open yuv file\n");
goto __FAIL;
}
refresh_thread = SDL_CreateThread(refresh_video,“refresh_video”,NULL);
do {
//Wait
SDL_WaitEvent(&event);
if(event.type==REFRESH_EVENT){
memset(frame_buf, 0, yuv_frame_size);
fread(frame_buf, 1, yuv_frame_size, file_fd);
//更新纹理
SDL_UpdateTexture(texture, NULL, frame_buf, video_width);
rect.x = 0;
rect.y = 0;
rect.w = video_width;
rect.h = video_height;
//清除渲染器，把纹理复制到渲染器，然后显示。
SDL_RenderClear(renderer);
SDL_RenderCopy(renderer, texture, NULL, &rect);
SDL_RenderPresent(renderer);
}else if(event.type==SDL_QUIT){
thread_exit = 1;
}else if(event.type==QUIT_EVENT){
break;
}
}while ( 1 );
__FAIL:
//close file
if(file_fd){
fclose(file_fd);
}
SDL_Quit();
return 0;
}
领取音视频开发学习资料：音视频开发（资料文档 视频教程 面试题）（FFmpeg WebRTC RTMP RTSP HLS RTP）
前面我们单独实现了简单的音乐播放和yuv视频播放。一个完整的播放器还需要解封装分离视频和音频数据，音视频数据解码以及音视频播放同步机制，也就是把上面两个demo组合起来加上ffmpeg解封装，解码和音视频同步就是一个完整的视频播放器啦。
编译命令：
gcc -o player6 player6.c -I /usr/local/include/SDL2/ -lSDL2 -lavcodec -lavutil -lavformat -lswresample -lswscale
完整的例子（参考ffplay源码精简的）
#include <stdio.h>
#include <assert.h>
#include <math.h>
#include <SDL.h>
#include <libavcodec/avcodec.h>
#include <libavformat/avformat.h>
#include <libswscale/swscale.h>
#include <libswresample/swresample.h>
// compatibility with newer API
#if LIBAVCODEC_VERSION_INT < AV_VERSION_INT(55,28,1)
#define av_frame_alloc avcodec_alloc_frame
#define av_frame_free avcodec_free_frame
#endif
#define SDL_AUDIO_BUFFER_SIZE 1024
#define MAX_AUDIO_FRAME_SIZE 192000 //channels(2) * data_size(2) * sample_rate(48000)
#define MAX_AUDIOQ_SIZE (5 * 16 * 1024)
#define MAX_VIDEOQ_SIZE (5 * 256 * 1024)
#define AV_SYNC_THRESHOLD 0.01
#define AV_NOSYNC_THRESHOLD 10.0
#define SAMPLE_CORRECTION_PERCENT_MAX 10
#define AUDIO_DIFF_AVG_NB 20
#define FF_REFRESH_EVENT (SDL_USEREVENT)
#define FF_QUIT_EVENT (SDL_USEREVENT 1)
#define VIDEO_PICTURE_QUEUE_SIZE 1
#define DEFAULT_AV_SYNC_TYPE AV_SYNC_AUDIO_MASTER //AV_SYNC_VIDEO_MASTER
typedef struct PacketQueue {
AVPacketList *first_pkt, *last_pkt;
int nb_packets;
int size;
SDL_mutex *mutex;
SDL_cond *cond;
} PacketQueue;
typedef struct VideoPicture {
AVPicture *bmp;
int width, height; /* source height & width */
int allocated;
double pts;
} VideoPicture;
typedef struct VideoState {
//multi-media file
char filename[1024];
AVFormatContext *pFormatCtx;
int videoStream, audioStream;
//sync
int av_sync_type;
double external_clock; /* external clock base */
int64_t external_clock_time;
double audio_diff_cum; /* used for AV difference average computation */
double audio_diff_avg_coef;
double audio_diff_threshold;
int audio_diff_avg_count;
double audio_clock;
double frame_timer;
double frame_last_pts;
double frame_last_delay;
double video_clock; ///<pts of last decoded frame / predicted pts of next decoded frame
double video_current_pts; ///<current displayed pts (different from video_clock if frame fifos are used)
int64_t video_current_pts_time; ///<time (av_gettime) at which we updated video_current_pts - used to have running video pts
//audio
AVStream *audio_st;
AVCodecContext *audio_ctx;
PacketQueue audioq;
uint8_t audio_buf[(MAX_AUDIO_FRAME_SIZE * 3) / 2];
unsigned int audio_buf_size;
unsigned int audio_buf_index;
AVFrame audio_frame;
AVPacket audio_pkt;
uint8_t *audio_pkt_data;
int audio_pkt_size;
int audio_hw_buf_size;
//video
AVStream *video_st;
AVCodecContext *video_ctx;
PacketQueue videoq;
struct SwsContext *video_sws_ctx;
struct SwrContext *audio_swr_ctx;
VideoPicture pictq[VIDEO_PICTURE_QUEUE_SIZE];
int pictq_size, pictq_rindex, pictq_windex;
SDL_mutex *pictq_mutex;
SDL_cond *pictq_cond;
SDL_Thread *parse_tid;
SDL_Thread *video_tid;
int quit;
} VideoState;
SDL_mutex *text_mutex;
SDL_Window *win = NULL;
SDL_Renderer *renderer;
SDL_Texture *texture;
enum {
AV_SYNC_AUDIO_MASTER,
AV_SYNC_VIDEO_MASTER,
AV_SYNC_EXTERNAL_MASTER,
};
FILE *yuvfd = NULL;
FILE *audiofd = NULL;
/* Since we only have one decoding thread, the Big Struct
can be global in case we need it. */
VideoState *global_video_state;
void packet_queue_init(PacketQueue *q) {
memset(q, 0, sizeof(PacketQueue));
q->mutex = SDL_CreateMutex();
q->cond = SDL_CreateCond();
}
int packet_queue_put(PacketQueue *q, AVPacket *pkt) {
AVPacketList *pkt1;
if(av_dup_packet(pkt) < 0) {
return -1;
}
pkt1 = av_malloc(sizeof(AVPacketList));
if (!pkt1)
return -1;
pkt1->pkt = *pkt;
pkt1->next = NULL;
SDL_LockMutex(q->mutex);
if (!q->last_pkt)
q->first_pkt = pkt1;
else
q->last_pkt->next = pkt1;
q->last_pkt = pkt1;
q->nb_packets ;
q->size = pkt1->pkt.size;
SDL_CondSignal(q->cond);
SDL_UnlockMutex(q->mutex);
return 0;
}
int packet_queue_get(PacketQueue *q, AVPacket *pkt, int block)
{
AVPacketList *pkt1;
int ret;
SDL_LockMutex(q->mutex);
for(;;) {
if(global_video_state->quit) {
ret = -1;
break;
}
pkt1 = q->first_pkt;
if (pkt1) {
q->first_pkt = pkt1->next;
if (!q->first_pkt)
q->last_pkt = NULL;
q->nb_packets--;
q->size -= pkt1->pkt.size;
*pkt = pkt1->pkt;
av_free(pkt1);
ret = 1;
break;
} else if (!block) {
ret = 0;
break;
} else {
SDL_CondWait(q->cond, q->mutex);
}
}
SDL_UnlockMutex(q->mutex);
return ret;
}
double get_audio_clock(VideoState *is) {
double pts;
int hw_buf_size, bytes_per_sec, n;
pts = is->audio_clock; /* maintained in the audio thread */
hw_buf_size = is->audio_buf_size - is->audio_buf_index;
bytes_per_sec = 0;
n = is->audio_ctx->channels * 2;
if(is->audio_st) {
bytes_per_sec = is->audio_ctx->sample_rate * n;
}
if(bytes_per_sec) {
pts -= (double)hw_buf_size / bytes_per_sec;
}
return pts;
}
double get_video_clock(VideoState *is) {
double delta;
delta = (av_gettime() - is->video_current_pts_time) / 1000000.0;
return is->video_current_pts delta;
}
double get_external_clock(VideoState *is) {
return av_gettime() / 1000000.0;
}
double get_master_clock(VideoState *is) {
if(is->av_sync_type == AV_SYNC_VIDEO_MASTER) {
return get_video_clock(is);
} else if(is->av_sync_type == AV_SYNC_AUDIO_MASTER) {
return get_audio_clock(is);
} else {
return get_external_clock(is);
}
}
/* Add or subtract samples to get a better sync, return new
audio buffer size */
int synchronize_audio(VideoState *is, short *samples,
int samples_size, double pts) {
int n;
double ref_clock;
n = 2 * is->audio_ctx->channels;
if(is->av_sync_type != AV_SYNC_AUDIO_MASTER) {
double diff, avg_diff;
int wanted_size, min_size, max_size /*, nb_samples */;
ref_clock = get_master_clock(is);
diff = get_audio_clock(is) - ref_clock;
if(diff < AV_NOSYNC_THRESHOLD) {
// accumulate the diffs
is->audio_diff_cum = diff is->audio_diff_avg_coef
* is->audio_diff_cum;
if(is->audio_diff_avg_count < AUDIO_DIFF_AVG_NB) {
is->audio_diff_avg_count ;
} else {
avg_diff = is->audio_diff_cum * (1.0 - is->audio_diff_avg_coef);
if(fabs(avg_diff) >= is->audio_diff_threshold) {
wanted_size = samples_size ((int)(diff * is->audio_ctx->sample_rate) * n);
min_size = samples_size * ((100 - SAMPLE_CORRECTION_PERCENT_MAX) / 100);
max_size = samples_size * ((100 SAMPLE_CORRECTION_PERCENT_MAX) / 100);
if(wanted_size < min_size) {
wanted_size = min_size;
} else if (wanted_size > max_size) {
wanted_size = max_size;
}
if(wanted_size < samples_size) {
/* remove samples */
samples_size = wanted_size;
} else if(wanted_size > samples_size) {
uint8_t *samples_end, *q;
int nb;
/* add samples by copying final sample*/
nb = (samples_size - wanted_size);
samples_end = (uint8_t *)samples samples_size - n;
q = samples_end n;
while(nb > 0) {
memcpy(q, samples_end, n);
q = n;
nb -= n;
}
samples_size = wanted_size;
}
}
}
} else {
/* difference is TOO big; reset diff stuff */
is->audio_diff_avg_count = 0;
is->audio_diff_cum = 0;
}
}
return samples_size;
}
int audio_decode_frame(VideoState *is, uint8_t *audio_buf, int buf_size, double *pts_ptr) {
int len1, data_size = 0;
AVPacket *pkt = &is->audio_pkt;
double pts;
int n;
for(;;) {
while(is->audio_pkt_size > 0) {
int got_frame = 0;
len1 = avcodec_decode_audio4(is->audio_ctx, &is->audio_frame, &got_frame, pkt);
if(len1 < 0) {
/* if error, skip frame */
is->audio_pkt_size = 0;
break;
}
data_size = 0;
if(got_frame) {
/*
data_size = av_samples_get_buffer_size(NULL,
is->audio_ctx->channels,
is->audio_frame.nb_samples,
is->audio_ctx->sample_fmt,
1);
*/
data_size = 2 * is->audio_frame.nb_samples * 2;
assert(data_size <= buf_size);
swr_convert(is->audio_swr_ctx,
&audio_buf,
MAX_AUDIO_FRAME_SIZE*3/2,
(const uint8_t **)is->audio_frame.data,
is->audio_frame.nb_samples);
fwrite(audio_buf, 1, data_size, audiofd);
//memcpy(audio_buf, is->audio_frame.data[0], data_size);
}
is->audio_pkt_data = len1;
is->audio_pkt_size -= len1;
if(data_size <= 0) {
/* No data yet, get more frames */
continue;
}
pts = is->audio_clock;
*pts_ptr = pts;
n = 2 * is->audio_ctx->channels;
is->audio_clock = (double)data_size /
(double)(n * is->audio_ctx->sample_rate);
/* We have data, return it and come back for more later */
return data_size;
}
if(pkt->data)
av_free_packet(pkt);
if(is->quit) {
return -1;
}
/* next packet */
if(packet_queue_get(&is->audioq, pkt, 1) < 0) {
return -1;
}
is->audio_pkt_data = pkt->data;
is->audio_pkt_size = pkt->size;
/* if update, update the audio clock w/pts */
if(pkt->pts != AV_NOPTS_VALUE) {
is->audio_clock = av_q2d(is->audio_st->time_base)*pkt->pts;
}
}
}
void audio_callback(void *userdata, Uint8 *stream, int len) {
VideoState *is = (VideoState *)userdata;
int len1, audio_size;
double pts;
SDL_memset(stream, 0, len);
while(len > 0) {
if(is->audio_buf_index >= is->audio_buf_size) {
/* We have already sent all our data; get more */
audio_size = audio_decode_frame(is, is->audio_buf, sizeof(is->audio_buf), &pts);
if(audio_size < 0) {
/* If error, output silence */
is->audio_buf_size = 1024 * 2 * 2;
memset(is->audio_buf, 0, is->audio_buf_size);
} else {
audio_size = synchronize_audio(is, (int16_t *)is->audio_buf,
audio_size, pts);
is->audio_buf_size = audio_size;
}
is->audio_buf_index = 0;
}
len1 = is->audio_buf_size - is->audio_buf_index;
if(len1 > len)
len1 = len;
SDL_MixAudio(stream,(uint8_t *)is->audio_buf is->audio_buf_index, len1, SDL_MIX_MAXVOLUME);
//memcpy(stream, (uint8_t *)is->audio_buf is->audio_buf_index, len1);
len -= len1;
stream = len1;
is->audio_buf_index = len1;
}
}
static Uint32 sdl_refresh_timer_cb(Uint32 interval, void *opaque) {
SDL_Event event;
event.type = FF_REFRESH_EVENT;
event.user.data1 = opaque;
SDL_PushEvent(&event);
return 0; /* 0 means stop timer */
}
/* schedule a video refresh in 'delay' ms */
static void schedule_refresh(VideoState *is, int delay) {
SDL_AddTimer(delay, sdl_refresh_timer_cb, is);
}
void video_display(VideoState *is) {
SDL_Rect rect;
VideoPicture *vp;
float aspect_ratio;
int w, h, x, y;
int i;
vp = &is->pictq[is->pictq_rindex];
if(vp->bmp) {
SDL_UpdateYUVTexture( texture, NULL,
vp->bmp->data[0], vp->bmp->linesize[0],
vp->bmp->data[1], vp->bmp->linesize[1],
vp->bmp->data[2], vp->bmp->linesize[2]);
rect.x = 0;
rect.y = 0;
rect.w = is->video_ctx->width;
rect.h = is->video_ctx->height;
SDL_LockMutex(text_mutex);
SDL_RenderClear( renderer );
SDL_RenderCopy( renderer, texture, NULL, &rect);
SDL_RenderPresent( renderer );
SDL_UnlockMutex(text_mutex);
}
}
void video_refresh_timer(void *userdata) {
VideoState *is = (VideoState *)userdata;
VideoPicture *vp;
double actual_delay, delay, sync_threshold, ref_clock, diff;
if(is->video_st) {
if(is->pictq_size == 0) {
schedule_refresh(is, 1);
//fprintf(stderr, "no picture in the queue!!!\n");
} else {
//fprintf(stderr, "get picture from queue!!!\n");
vp = &is->pictq[is->pictq_rindex];
is->video_current_pts = vp->pts;
is->video_current_pts_time = av_gettime();
delay = vp->pts - is->frame_last_pts; /* the pts from last time */
if(delay <= 0 || delay >= 1.0) {
/* if incorrect delay, use previous one */
delay = is->frame_last_delay;
}
/* save for next time */
is->frame_last_delay = delay;
is->frame_last_pts = vp->pts;
/* update delay to sync to audio if not master source */
if(is->av_sync_type != AV_SYNC_VIDEO_MASTER) {
ref_clock = get_master_clock(is);
diff = vp->pts - ref_clock;
/* Skip or repeat the frame. Take delay into account
FFPlay still doesn't "know if this is the best guess." */
sync_threshold = (delay > AV_SYNC_THRESHOLD) ? delay : AV_SYNC_THRESHOLD;
if(fabs(diff) < AV_NOSYNC_THRESHOLD) {
if(diff <= -sync_threshold) {
delay = 0;
} else if(diff >= sync_threshold) {
delay = 2 * delay;
}
}
}
is->frame_timer = delay;
/* computer the REAL delay */
actual_delay = is->frame_timer - (av_gettime() / 1000000.0);
if(actual_delay < 0.010) {
/* Really it should skip the picture instead */
actual_delay = 0.010;
}
schedule_refresh(is, (int)(actual_delay * 1000 0.5));
/* show the picture! */
video_display(is);
/* update queue for next picture! */
if( is->pictq_rindex == VIDEO_PICTURE_QUEUE_SIZE) {
is->pictq_rindex = 0;
}
SDL_LockMutex(is->pictq_mutex);
is->pictq_size--;
SDL_CondSignal(is->pictq_cond);
SDL_UnlockMutex(is->pictq_mutex);
}
} else {
schedule_refresh(is, 100);
}
}
void alloc_picture(void *userdata) {
int ret;
VideoState *is = (VideoState *)userdata;
VideoPicture *vp;
vp = &is->pictq[is->pictq_windex];
if(vp->bmp) {
// we already have one make another, bigger/smaller
avpicture_free(vp->bmp);
free(vp->bmp);
vp->bmp = NULL;
}
// Allocate a place to put our YUV image on that screen
SDL_LockMutex(text_mutex);
vp->bmp = (AVPicture*)malloc(sizeof(AVPicture));
ret = avpicture_alloc(vp->bmp, AV_PIX_FMT_YUV420P, is->video_ctx->width, is->video_ctx->height);
if (ret < 0) {
fprintf(stderr, "Could not allocate temporary picture: %s\n", av_err2str(ret));
}
SDL_UnlockMutex(text_mutex);
vp->width = is->video_ctx->width;
vp->height = is->video_ctx->height;
vp->allocated = 1;
}
int queue_picture(VideoState *is, AVFrame *pFrame, double pts) {
VideoPicture *vp;
/* wait until we have space for a new pic */
SDL_LockMutex(is->pictq_mutex);
while(is->pictq_size >= VIDEO_PICTURE_QUEUE_SIZE &&
!is->quit) {
SDL_CondWait(is->pictq_cond, is->pictq_mutex);
}
SDL_UnlockMutex(is->pictq_mutex);
if(is->quit)
return -1;
// windex is set to 0 initially
vp = &is->pictq[is->pictq_windex];
/* allocate or resize the buffer! */
if(!vp->bmp ||
vp->width != is->video_ctx->width ||
vp->height != is->video_ctx->height) {
vp->allocated = 0;
alloc_picture(is);
if(is->quit) {
return -1;
}
}
/* We have a place to put our picture on the queue */
if(vp->bmp) {
vp->pts = pts;
// Convert the image into YUV format that SDL uses
sws_scale(is->video_sws_ctx, (uint8_t const * const *)pFrame->data,
pFrame->linesize, 0, is->video_ctx->height,
vp->bmp->data, vp->bmp->linesize);
/* now we inform our display thread that we have a pic ready */
if( is->pictq_windex == VIDEO_PICTURE_QUEUE_SIZE) {
is->pictq_windex = 0;
}
SDL_LockMutex(is->pictq_mutex);
is->pictq_size ;
SDL_UnlockMutex(is->pictq_mutex);
}
return 0;
}
double synchronize_video(VideoState *is, AVFrame *src_frame, double pts) {
double frame_delay;
if(pts != 0) {
/* if we have pts, set video clock to it */
is->video_clock = pts;
} else {
/* if we aren't given a pts, set it to the clock */
pts = is->video_clock;
}
/* update the video clock */
frame_delay = av_q2d(is->video_ctx->time_base);
/* if we are repeating a frame, adjust clock accordingly */
frame_delay = src_frame->repeat_pict * (frame_delay * 0.5);
is->video_clock = frame_delay;
return pts;
}
int decode_video_thread(void *arg) {
VideoState *is = (VideoState *)arg;
AVPacket pkt1, *packet = &pkt1;
int frameFinished;
AVFrame *pFrame;
double pts;
pFrame = av_frame_alloc();
for(;;) {
if(packet_queue_get(&is->videoq, packet, 1) < 0) {
// means we quit getting packets
break;
}
pts = 0;
// Decode video frame
avcodec_decode_video2(is->video_ctx, pFrame, &frameFinished, packet);
if((pts = av_frame_get_best_effort_timestamp(pFrame)) != AV_NOPTS_VALUE) {
} else {
pts = 0;
}
pts *= av_q2d(is->video_st->time_base);
// Did we get a video frame?
if(frameFinished) {
pts = synchronize_video(is, pFrame, pts);
if(queue_picture(is, pFrame, pts) < 0) {
break;
}
}
av_free_packet(packet);
}
av_frame_free(&pFrame);
return 0;
}
int stream_component_open(VideoState *is, int stream_index) {
AVFormatContext *pFormatCtx = is->pFormatCtx;
AVCodecContext *codecCtx = NULL;
AVCodec *codec = NULL;
SDL_AudioSpec wanted_spec, spec;
if(stream_index < 0 || stream_index >= pFormatCtx->nb_streams) {
return -1;
}
codecCtx = avcodec_alloc_context3(NULL);
int ret = avcodec_parameters_to_context(codecCtx, pFormatCtx->streams[stream_index]->codecpar);
if (ret < 0)
return -1;
codec = avcodec_find_decoder(codecCtx->codec_id);
if(!codec) {
fprintf(stderr, "Unsupported codec!\n");
return -1;
}
if(codecCtx->codec_type == AVMEDIA_TYPE_AUDIO) {
// Set audio settings from codec info
wanted_spec.freq = codecCtx->sample_rate;
wanted_spec.format = AUDIO_S16SYS;
wanted_spec.channels = 2;//codecCtx->channels;
wanted_spec.silence = 0;
wanted_spec.samples = SDL_AUDIO_BUFFER_SIZE;
wanted_spec.callback = audio_callback;
wanted_spec.userdata = is;
fprintf(stderr, "wanted spec: channels:%d, sample_fmt:%d, sample_rate:%d \n",
2, AUDIO_S16SYS, codecCtx->sample_rate);
if(SDL_OpenAudio(&wanted_spec, &spec) < 0) {
fprintf(stderr, "SDL_OpenAudio: %s\n", SDL_GetError());
return -1;
}
is->audio_hw_buf_size = spec.size;
}
if(avcodec_open2(codecCtx, codec, NULL) < 0) {
fprintf(stderr, "Unsupported codec!\n");
return -1;
}
switch(codecCtx->codec_type) {
case AVMEDIA_TYPE_AUDIO:
is->audioStream = stream_index;
is->audio_st = pFormatCtx->streams[stream_index];
is->audio_ctx = codecCtx;
is->audio_buf_size = 0;
is->audio_buf_index = 0;
memset(&is->audio_pkt, 0, sizeof(is->audio_pkt));
packet_queue_init(&is->audioq);
//Out Audio Param
uint64_t out_channel_layout=AV_CH_LAYOUT_STEREO;
//AAC:1024 MP3:1152
int out_nb_samples= is->audio_ctx->frame_size;
//AVSampleFormat out_sample_fmt = AV_SAMPLE_FMT_S16;
int out_sample_rate=is->audio_ctx->sample_rate;
int out_channels=av_get_channel_layout_nb_channels(out_channel_layout);
//Out Buffer Size
/*
int out_buffer_size=av_samples_get_buffer_size(NULL,
out_channels,
out_nb_samples,
AV_SAMPLE_FMT_S16,
1);
*/
//uint8_t *out_buffer=(uint8_t *)av_malloc(MAX_AUDIO_FRAME_SIZE*2);
int64_t in_channel_layout=av_get_default_channel_layout(is->audio_ctx->channels);
struct SwrContext *audio_convert_ctx;
audio_convert_ctx = swr_alloc();
swr_alloc_set_opts(audio_convert_ctx,
out_channel_layout,
AV_SAMPLE_FMT_S16,
out_sample_rate,
in_channel_layout,
is->audio_ctx->sample_fmt,
is->audio_ctx->sample_rate,
0,
NULL);
fprintf(stderr, "swr opts: out_channel_layout:%lld, out_sample_fmt:%d, out_sample_rate:%d, in_channel_layout:%lld, in_sample_fmt:%d, in_sample_rate:%d",
out_channel_layout, AV_SAMPLE_FMT_S16, out_sample_rate, in_channel_layout, is->audio_ctx->sample_fmt, is->audio_ctx->sample_rate);
swr_init(audio_convert_ctx);
is->audio_swr_ctx = audio_convert_ctx;
SDL_PauseAudio(0);
break;
case AVMEDIA_TYPE_VIDEO:
is->videoStream = stream_index;
is->video_st = pFormatCtx->streams[stream_index];
is->video_ctx = codecCtx;
is->frame_timer = (double)av_gettime() / 1000000.0;
is->frame_last_delay = 40e-3;
is->video_current_pts_time = av_gettime();
packet_queue_init(&is->videoq);
is->video_sws_ctx = sws_getContext(is->video_ctx->width, is->video_ctx->height,
is->video_ctx->pix_fmt, is->video_ctx->width,
is->video_ctx->height, AV_PIX_FMT_YUV420P,
SWS_BILINEAR, NULL, NULL, NULL
);
is->video_tid = SDL_CreateThread(decode_video_thread, "decode_video_thread", is);
break;
default:
break;
}
}
int demux_thread(void *arg) {
int err_code;
char errors[1024] = {0,};
VideoState *is = (VideoState *)arg;
AVFormatContext *pFormatCtx;
AVPacket pkt1, *packet = &pkt1;
int video_index = -1;
int audio_index = -1;
int i;
is->videoStream=-1;
is->audioStream=-1;
global_video_state = is;
/* open input file, and allocate format context */
if ((err_code=avformat_open_input(&pFormatCtx, is->filename, NULL, NULL)) < 0) {
av_strerror(err_code, errors, 1024);
fprintf(stderr, "Could not open source file %s, %d(%s)\n", is->filename, err_code, errors);
return -1;
}
is->pFormatCtx = pFormatCtx;
// Retrieve stream information
if(avformat_find_stream_info(pFormatCtx, NULL)<0)
return -1; // Couldn't find stream information
// Dump information about file onto standard error
av_dump_format(pFormatCtx, 0, is->filename, 0);
// Find the first video stream
for(i=0; i<pFormatCtx->nb_streams; i ) {
if(pFormatCtx->streams[i]->codec->codec_type==AVMEDIA_TYPE_VIDEO &&
video_index < 0) {
video_index=i;
}
if(pFormatCtx->streams[i]->codec->codec_type==AVMEDIA_TYPE_AUDIO &&
audio_index < 0) {
audio_index=i;
}
}
if(audio_index >= 0) {
stream_component_open(is, audio_index);
}
if(video_index >= 0) {
stream_component_open(is, video_index);
}
if(is->videoStream < 0 || is->audioStream < 0) {
fprintf(stderr, "%s: could not open codecs\n", is->filename);
goto fail;
}
//creat window from SDL
win = SDL_CreateWindow("Media Player",
SDL_WINDOWPOS_UNDEFINED,
SDL_WINDOWPOS_UNDEFINED,
is->video_ctx->width, is->video_ctx->height,
SDL_WINDOW_OPENGL|SDL_WINDOW_RESIZABLE);
if(!win) {
fprintf(stderr, "SDL: could not set video mode - exiting\n");
exit(1);
}
renderer = SDL_CreateRenderer(win, -1, 0);
//IYUV: Y U V (3 planes)
//YV12: Y V U (3 planes)
Uint32 pixformat= SDL_PIXELFORMAT_IYUV;
//create texture for render
texture = SDL_CreateTexture(renderer,
pixformat,
SDL_TEXTUREACCESS_STREAMING,
is->video_ctx->width,
is->video_ctx->height);
// main decode loop
for(;;) {
if(is->quit) {
break;
}
// seek stuff goes here
if(is->audioq.size > MAX_AUDIOQ_SIZE ||
is->videoq.size > MAX_VIDEOQ_SIZE) {
SDL_Delay(10);
continue;
}
if(av_read_frame(is->pFormatCtx, packet) < 0) {
if(is->pFormatCtx->pb->error == 0) {
SDL_Delay(100); /* no error; wait for user input */
continue;
} else {
break;
}
}
// Is this a packet from the video stream?
if(packet->stream_index == is->videoStream) {
packet_queue_put(&is->videoq, packet);
} else if(packet->stream_index == is->audioStream) {
packet_queue_put(&is->audioq, packet);
} else {
av_free_packet(packet);
}
}
/* all done - wait for it */
while(!is->quit) {
SDL_Delay(100);
}
fail:
if(1){
SDL_Event event;
event.type = FF_QUIT_EVENT;
event.user.data1 = is;
SDL_PushEvent(&event);
}
return 0;
}
int main(int argc, char *argv[]) {
SDL_Event event;
VideoState *is;
is = av_mallocz(sizeof(VideoState));
if(argc < 2) {
fprintf(stderr, "Usage: test <file>\n");
exit(1);
}
yuvfd = fopen("testout.yuv", "wb ");
audiofd = fopen("testout.pcm", "wb ");
// Register all formats and codecs
av_register_all();
if(SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_TIMER)) {
fprintf(stderr, "Could not initialize SDL - %s\n", SDL_GetError());
exit(1);
}
text_mutex = SDL_CreateMutex();
av_strlcpy(is->filename, argv[1], sizeof(is->filename));
is->pictq_mutex = SDL_CreateMutex();
is->pictq_cond = SDL_CreateCond();
schedule_refresh(is, 40);
is->av_sync_type = DEFAULT_AV_SYNC_TYPE;
is->parse_tid = SDL_CreateThread(demux_thread,"demux_thread", is);
if(!is->parse_tid) {
av_free(is);
return -1;
}
for(;;) {
SDL_WaitEvent(&event);
switch(event.type) {
case FF_QUIT_EVENT:
case SDL_QUIT:
is->quit = 1;
SDL_Quit();
return 0;
break;
case FF_REFRESH_EVENT:
video_refresh_timer(event.user.data1);
break;
default:
break;
}
}
fclose(yuvfd);
fclose(audiofd);
return 0;
}
