如何在Android用FFmpeg+SDL2.0之同步音频
来源:互联网 发布:CVI ibevent windows 编辑:程序博客网 时间:2024/06/05 23:45
http://blog.csdn.net/tanlon_0308/article/details/40428139
版权声明:本文为博主原创文章,未经博主允许不得转载。
同步音频的原理可以参考:http://dranger.com/ffmpeg/tutorial05.html 本文是在 如何在Android用FFmpeg+SDL2.0之同步视频 的基础上面继续进行将视频和音频同步到外部时钟的工作,同时也包含了修正音频解码的问题。
- /*
- * SDL_Lesson.c
- *
- * Created on: Aug 12, 2014
- * Author: clarck
- */
- #include <jni.h>
- #include <android/native_window_jni.h>
- #include "SDL.h"
- #include "SDL_thread.h"
- #include "SDL_events.h"
- #include "../include/logger.h"
- #include "../ffmpeg/include/libavcodec/avcodec.h"
- #include "../ffmpeg/include/libavformat/avformat.h"
- #include "../ffmpeg/include/libavutil/pixfmt.h"
- #include "../ffmpeg/include/libswscale/swscale.h"
- #include "../ffmpeg/include/libswresample/swresample.h"
- #define SDL_AUDIO_BUFFER_SIZE 1024
- #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_ALLOC_EVENT (SDL_USEREVENT)
- #define FF_REFRESH_EVENT (SDL_USEREVENT + 1)
- #define FF_QUIT_EVENT (SDL_USEREVENT + 2)
- #define VIDEO_PICTURE_QUEUE_SIZE 1
- #define DEFAULT_AV_SYNC_TYPE AV_SYNC_VIDEO_MASTER
- #define AVCODEC_MAX_AUDIO_FRAME_SIZE 192000 // 1 second of 48khz 32bit audio
- typedef struct PacketQueue {
- AVPacketList *first_pkt, *last_pkt;
- int nb_packets;
- int size;
- SDL_mutex *mutex;
- SDL_cond *cond;
- } PacketQueue;
- typedef struct VideoPicture {
- SDL_Window *screen;
- SDL_Renderer *renderer;
- SDL_Texture *bmp;
- AVFrame* rawdata;
- int width, height; /*source height & width*/
- int allocated;
- double pts;
- } VideoPicture;
- typedef struct VideoState {
- char filename[1024];
- AVFormatContext *ic;
- int videoStream, audioStream;
- AVStream *audio_st;
- AVFrame *audio_frame;
- PacketQueue audioq;
- unsigned int audio_buf_size;
- unsigned int audio_buf_index;
- AVPacket audio_pkt;
- uint8_t *audio_pkt_data;
- int audio_pkt_size;
- uint8_t *audio_buf;
- DECLARE_ALIGNED(16,uint8_t,audio_buf2) [AVCODEC_MAX_AUDIO_FRAME_SIZE * 4];
- enum AVSampleFormat audio_src_fmt;
- enum AVSampleFormat audio_tgt_fmt;
- int audio_src_channels;
- int audio_tgt_channels;
- int64_t audio_src_channel_layout;
- int64_t audio_tgt_channel_layout;
- int audio_src_freq;
- int audio_tgt_freq;
- struct SwrContext *swr_ctx;
- AVStream *video_st;
- PacketQueue videoq;
- 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 *audio_tid;
- SDL_Thread *video_tid;
- AVIOContext *io_ctx;
- struct SwsContext *sws_ctx;
- double audio_clock;
- int av_sync_type;
- double external_clock;/*external clock base*/
- int64_t external_clock_time;
- int audio_hw_buf_size;
- double audio_diff_cum;/*used of AV difference average computation*/
- double audio_diff_avg_coef;
- double audio_diff_threshold;
- int audio_diff_avg_count;
- double frame_timer;
- double frame_last_pts;
- double frame_last_delay;
- 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
- double video_clock; ///<pts of last decoded frame / predicted pts of next decoded frame
- int quit;
- } VideoState;
- enum {
- AV_SYNC_AUDIO_MASTER, AV_SYNC_VIDEO_MASTER, AV_SYNC_EXTERNAL_MASTER,
- };
- 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;
- pkt1 = (AVPacketList *) 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;
- }
- static 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_st->codec->channels * 2;
- if (is->audio_st) {
- bytes_per_sec = is->audio_st->codec->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_st->codec->channels;
- if (is->av_sync_type != AV_SYNC_AUDIO_MASTER) {
- double diff, avg_diff;
- int wanted_size, min_size, max_size;
- //int 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_st->codec->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, double *pts_ptr) {
- int len1, len2, decoded_data_size;
- AVPacket *pkt = &is->audio_pkt;
- int got_frame = 0;
- int64_t dec_channel_layout;
- int wanted_nb_samples, resampled_data_size, n;
- double pts;
- for (;;) {
- while (is->audio_pkt_size > 0) {
- if (!is->audio_frame) {
- if (!(is->audio_frame = avcodec_alloc_frame())) {
- return AVERROR(ENOMEM);
- }
- } else
- avcodec_get_frame_defaults(is->audio_frame);
- len1 = avcodec_decode_audio4(is->audio_st->codec, is->audio_frame,
- &got_frame, pkt);
- if (len1 < 0) {
- // error, skip the frame
- is->audio_pkt_size = 0;
- break;
- }
- is->audio_pkt_data += len1;
- is->audio_pkt_size -= len1;
- if (!got_frame)
- continue;
- /* 计算解码出来的桢需要的缓冲大小 */
- decoded_data_size = av_samples_get_buffer_size(NULL,
- is->audio_frame->channels, is->audio_frame->nb_samples,
- is->audio_frame->format, 1);
- dec_channel_layout =
- (is->audio_frame->channel_layout
- && is->audio_frame->channels
- == av_get_channel_layout_nb_channels(
- is->audio_frame->channel_layout)) ?
- is->audio_frame->channel_layout :
- av_get_default_channel_layout(
- is->audio_frame->channels);
- wanted_nb_samples = is->audio_frame->nb_samples;
- if (is->audio_frame->format != is->audio_src_fmt
- || dec_channel_layout != is->audio_src_channel_layout
- || is->audio_frame->sample_rate != is->audio_src_freq
- || (wanted_nb_samples != is->audio_frame->nb_samples
- && !is->swr_ctx)) {
- if (is->swr_ctx)
- swr_free(&is->swr_ctx);
- is->swr_ctx = swr_alloc_set_opts(NULL,
- is->audio_tgt_channel_layout, is->audio_tgt_fmt,
- is->audio_tgt_freq, dec_channel_layout,
- is->audio_frame->format, is->audio_frame->sample_rate,
- 0, NULL);
- if (!is->swr_ctx || swr_init(is->swr_ctx) < 0) {
- fprintf(stderr, "swr_init() failed\n");
- break;
- }
- is->audio_src_channel_layout = dec_channel_layout;
- is->audio_src_channels = is->audio_st->codec->channels;
- is->audio_src_freq = is->audio_st->codec->sample_rate;
- is->audio_src_fmt = is->audio_st->codec->sample_fmt;
- }
- /* 这里我们可以对采样数进行调整,增加或者减少,一般可以用来做声画同步 */
- if (is->swr_ctx) {
- const uint8_t **in =
- (const uint8_t **) is->audio_frame->extended_data;
- uint8_t *out[] = { is->audio_buf2 };
- if (wanted_nb_samples != is->audio_frame->nb_samples) {
- if (swr_set_compensation(is->swr_ctx,
- (wanted_nb_samples - is->audio_frame->nb_samples)
- * is->audio_tgt_freq
- / is->audio_frame->sample_rate,
- wanted_nb_samples * is->audio_tgt_freq
- / is->audio_frame->sample_rate) < 0) {
- fprintf(stderr, "swr_set_compensation() failed\n");
- break;
- }
- }
- len2 = swr_convert(is->swr_ctx, out,
- sizeof(is->audio_buf2) / is->audio_tgt_channels
- / av_get_bytes_per_sample(is->audio_tgt_fmt),
- in, is->audio_frame->nb_samples);
- if (len2 < 0) {
- fprintf(stderr, "swr_convert() failed\n");
- break;
- }
- if (len2
- == sizeof(is->audio_buf2) / is->audio_tgt_channels
- / av_get_bytes_per_sample(is->audio_tgt_fmt)) {
- fprintf(stderr,
- "warning: audio buffer is probably too small\n");
- swr_init(is->swr_ctx);
- }
- is->audio_buf = is->audio_buf2;
- resampled_data_size = len2 * is->audio_tgt_channels
- * av_get_bytes_per_sample(is->audio_tgt_fmt);
- } else {
- resampled_data_size = decoded_data_size;
- is->audio_buf = is->audio_frame->data[0];
- }
- pts = is->audio_clock;
- *pts_ptr = pts;
- n = 2 * is->audio_st->codec->channels;
- is->audio_clock += (double) resampled_data_size
- / (double) (n * is->audio_st->codec->sample_rate);
- // We have data, return it and come back for more later
- return resampled_data_size;
- }
- if (pkt->data)
- av_free_packet(pkt);
- memset(pkt, 0, sizeof(*pkt));
- if (is->quit)
- return -1;
- 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;
- }
- }
- return 0;
- }
- void audio_callback(void *userdata, Uint8 *stream, int len) {
- VideoState *is = (VideoState *) userdata;
- int len1, audio_data_size;
- double pts;
- /* len是由SDL传入的SDL缓冲区的大小,如果这个缓冲未满,我们就一直往里填充数据 */
- while (len > 0) {
- /* audio_buf_index 和 audio_buf_size 标示我们自己用来放置解码出来的数据的缓冲区,*/
- /* 这些数据待copy到SDL缓冲区, 当audio_buf_index >= audio_buf_size的时候意味着我*/
- /* 们的缓冲为空,没有数据可供copy,这时候需要调用audio_decode_frame来解码出更
- /* 多的桢数据 */
- if (is->audio_buf_index >= is->audio_buf_size) {
- audio_data_size = audio_decode_frame(is, &pts);
- /* audio_data_size < 0 标示没能解码出数据,我们默认播放静音 */
- if (audio_data_size < 0) {
- /* silence */
- is->audio_buf_size = 1024;
- /* 清零,静音 */
- memset(is->audio_buf, 0, is->audio_buf_size);
- } else {
- audio_data_size = synchronize_audio(is, (int16_t *) is->audio_buf,
- audio_data_size, pts);
- is->audio_buf_size = audio_data_size;
- }
- is->audio_buf_index = 0;
- }
- /* 查看stream可用空间,决定一次copy多少数据,剩下的下次继续copy */
- len1 = is->audio_buf_size - is->audio_buf_index;
- if (len1 > len) {
- len1 = len;
- }
- 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;
- }
- static void schedule_refresh(VideoState *is, int delay) {
- SDL_AddTimer(delay, sdl_refresh_timer_cb, is);
- }
- int decode_interrupt_cb(void *opaque) {
- return (global_video_state && global_video_state->quit);
- }
- void video_display(VideoState *is) {
- SDL_Rect rect;
- VideoPicture *vp;
- float aspect_ratio;
- vp = &is->pictq[is->pictq_rindex];
- if (vp->bmp) {
- if (is->video_st->codec->sample_aspect_ratio.num == 0) {
- aspect_ratio = 0;
- } else {
- aspect_ratio = av_q2d(is->video_st->codec->sample_aspect_ratio)
- * is->video_st->codec->width / is->video_st->codec->height;
- }
- if (aspect_ratio <= 0.0) {
- aspect_ratio = (float) is->video_st->codec->width
- / (float) is->video_st->codec->height;
- }
- rect.x = 0;
- rect.y = 0;
- rect.w = vp->width;
- rect.h = vp->height;
- SDL_UpdateYUVTexture(vp->bmp, &rect, vp->rawdata->data[0],
- vp->rawdata->linesize[0], vp->rawdata->data[1],
- vp->rawdata->linesize[1], vp->rawdata->data[2],
- vp->rawdata->linesize[2]);
- SDL_RenderClear(vp->renderer);
- SDL_RenderCopy(vp->renderer, vp->bmp, &rect, &rect);
- SDL_RenderPresent(vp->renderer);
- }
- }
- 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);
- } else {
- 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 */
- ref_clock = get_audio_clock(is);
- diff = vp->pts - ref_clock;
- /* 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) {
- VideoState *is = (VideoState *) userdata;
- VideoPicture *vp;
- vp = &is->pictq[is->pictq_windex];
- if (vp->bmp) {
- // we already have one make another, bigger/smaller
- SDL_DestroyTexture(vp->bmp);
- }
- if(vp->rawdata) {
- av_free(vp->rawdata);
- }
- // Allocate a place to put our YUV image on that screen
- vp->screen = SDL_CreateWindow("My Player Window", SDL_WINDOWPOS_UNDEFINED,
- SDL_WINDOWPOS_UNDEFINED, is->video_st->codec->width,
- is->video_st->codec->height,
- SDL_WINDOW_FULLSCREEN | SDL_WINDOW_OPENGL);
- vp->renderer = SDL_CreateRenderer(vp->screen, -1, 0);
- vp->bmp = SDL_CreateTexture(vp->renderer, SDL_PIXELFORMAT_YV12,
- SDL_TEXTUREACCESS_STREAMING, is->video_st->codec->width, is->video_st->codec->height);
- vp->width = is->video_st->codec->width;
- vp->height = is->video_st->codec->height;
- AVFrame* pFrameYUV = avcodec_alloc_frame();
- if (pFrameYUV == NULL)
- return;
- int numBytes = avpicture_get_size(PIX_FMT_YUV420P, vp->width,
- vp->height);
- uint8_t* buffer = (uint8_t *) av_malloc(numBytes * sizeof(uint8_t));
- avpicture_fill((AVPicture *) pFrameYUV, buffer, PIX_FMT_YUV420P,
- vp->width, vp->height);
- vp->rawdata = pFrameYUV;
- SDL_LockMutex(is->pictq_mutex);
- vp->allocated = 1;
- SDL_CondSignal(is->pictq_cond);
- SDL_UnlockMutex(is->pictq_mutex);
- }
- int queue_picture(VideoState *is, AVFrame *pFrame, double pts) {
- VideoPicture *vp;
- //int dst_pic_fmt
- AVPicture pict;
- /* wait unitl 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_st->codec->width
- || vp->height != is->video_st->codec->height) {
- SDL_Event event;
- vp->allocated = 0;
- /* we have to do it in the main thread */
- event.type = FF_ALLOC_EVENT;
- event.user.data1 = is;
- SDL_PushEvent(&event);
- /* wait until we have a picture allocated */
- SDL_LockMutex(is->pictq_mutex);
- while (!vp->allocated && !is->quit) {
- SDL_CondWait(is->pictq_cond, is->pictq_mutex);
- }
- }
- SDL_UnlockMutex(is->pictq_mutex);
- if (is->quit) {
- return -1;
- }
- /* We have a place to put our picture on the queue */
- if (vp->rawdata) {
- // Convert the image into YUV format that SDL uses
- sws_scale(is->sws_ctx, (uint8_t const * const *) pFrame->data,
- pFrame->linesize, 0, is->video_st->codec->height,
- vp->rawdata->data, vp->rawdata->linesize);
- vp->pts = pts;
- /* 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_st->codec->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;
- }
- uint64_t global_video_pkt_pts = AV_NOPTS_VALUE;
- /* These are called whenever we allocate a frame
- * buffer. We use this to store the global_pts in
- * a frame at the time it is allocated.
- */
- int our_get_buffer(struct AVCodecContext *c, AVFrame *pic) {
- int ret = avcodec_default_get_buffer(c, pic);
- uint64_t *pts = av_malloc(sizeof(uint64_t));
- *pts = global_video_pkt_pts;
- pic->opaque = pts;
- return ret;
- }
- void our_release_buffer(struct AVCodecContext *c, AVFrame *pic) {
- if (pic)
- av_freep(&pic->opaque);
- avcodec_default_release_buffer(c, pic);
- }
- int 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;
- // Save global pts to be stored in pFrame in first call
- global_video_pkt_pts = packet->pts;
- // Decode video frame
- avcodec_decode_video2(is->video_st->codec, pFrame, &frameFinished,
- packet);
- if (packet->dts == AV_NOPTS_VALUE && pFrame->opaque
- && *(uint64_t*) pFrame->opaque != AV_NOPTS_VALUE) {
- pts = *(uint64_t *) pFrame->opaque;
- } else if (packet->dts != AV_NOPTS_VALUE) {
- pts = packet->dts;
- } 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_free(pFrame);
- return 0;
- }
- int audio_stream_component_open(VideoState *is, int stream_index) {
- AVFormatContext *ic = is->ic;
- AVCodecContext *codecCtx;
- AVCodec *codec;
- SDL_AudioSpec wanted_spec, spec;
- int64_t wanted_channel_layout = 0;
- int wanted_nb_channels;
- /* SDL支持的声道数为 1, 2, 4, 6 */
- /* 后面我们会使用这个数组来纠正不支持的声道数目 */
- const int next_nb_channels[] = { 0, 0, 1, 6, 2, 6, 4, 6 };
- if (stream_index < 0 || stream_index >= ic->nb_streams) {
- return -1;
- }
- codecCtx = ic->streams[stream_index]->codec;
- wanted_nb_channels = codecCtx->channels;
- if (!wanted_channel_layout
- || wanted_nb_channels
- != av_get_channel_layout_nb_channels(
- wanted_channel_layout)) {
- wanted_channel_layout = av_get_default_channel_layout(
- wanted_nb_channels);
- wanted_channel_layout &= ~AV_CH_LAYOUT_STEREO_DOWNMIX;
- }
- wanted_spec.channels = av_get_channel_layout_nb_channels(
- wanted_channel_layout);
- wanted_spec.freq = codecCtx->sample_rate;
- if (wanted_spec.freq <= 0 || wanted_spec.channels <= 0) {
- fprintf(stderr, "Invalid sample rate or channel count!\n");
- return -1;
- }
- wanted_spec.format = AUDIO_S16SYS; // 具体含义请查看“SDL宏定义”部分
- wanted_spec.silence = 0; // 0指示静音
- wanted_spec.samples = SDL_AUDIO_BUFFER_SIZE; // 自定义SDL缓冲区大小
- wanted_spec.callback = audio_callback; // 音频解码的关键回调函数
- wanted_spec.userdata = is; // 传给上面回调函数的外带数据
- /* 打开音频设备,这里使用一个while来循环尝试打开不同的声道数(由上面 */
- /* next_nb_channels数组指定)直到成功打开,或者全部失败 */
- while (SDL_OpenAudio(&wanted_spec, &spec) < 0) {
- fprintf(stderr, "SDL_OpenAudio (%d channels): %s\n",
- wanted_spec.channels, SDL_GetError());
- wanted_spec.channels = next_nb_channels[FFMIN(7, wanted_spec.channels)];
- if (!wanted_spec.channels) {
- fprintf(stderr,
- "No more channel combinations to tyu, audio open failed\n");
- return -1;
- }
- wanted_channel_layout = av_get_default_channel_layout(
- wanted_spec.channels);
- }
- /* 检查实际使用的配置(保存在spec,由SDL_OpenAudio()填充) */
- if (spec.format != AUDIO_S16SYS) {
- fprintf(stderr, "SDL advised audio format %d is not supported!\n",
- spec.format);
- return -1;
- }
- if (spec.channels != wanted_spec.channels) {
- wanted_channel_layout = av_get_default_channel_layout(spec.channels);
- if (!wanted_channel_layout) {
- fprintf(stderr, "SDL advised channel count %d is not supported!\n",
- spec.channels);
- return -1;
- }
- }
- is->audio_hw_buf_size = spec.size;
- /* 把设置好的参数保存到大结构中 */
- is->audio_src_fmt = is->audio_tgt_fmt = AV_SAMPLE_FMT_S16;
- is->audio_src_freq = is->audio_tgt_freq = spec.freq;
- is->audio_src_channel_layout = is->audio_tgt_channel_layout =
- wanted_channel_layout;
- is->audio_src_channels = is->audio_tgt_channels = spec.channels;
- codec = avcodec_find_decoder(codecCtx->codec_id);
- if (!codec || (avcodec_open2(codecCtx, codec, NULL) < 0)) {
- fprintf(stderr, "Unsupported codec!\n");
- return -1;
- }
- ic->streams[stream_index]->discard = AVDISCARD_DEFAULT;
- switch (codecCtx->codec_type) {
- case AVMEDIA_TYPE_AUDIO:
- is->audioStream = stream_index;
- is->audio_st = ic->streams[stream_index];
- is->audio_buf_size = 0;
- is->audio_buf_index = 0;
- /* averaging filter for audio sync */
- is->audio_diff_avg_coef = exp(log(0.01 / AUDIO_DIFF_AVG_NB));
- is->audio_diff_avg_count = 0;
- /* Correct audio only if larger error than this */
- is->audio_diff_threshold = 2.0 * SDL_AUDIO_BUFFER_SIZE
- / codecCtx->sample_rate;
- memset(&is->audio_pkt, 0, sizeof(is->audio_pkt));
- packet_queue_init(&is->audioq);
- SDL_PauseAudio(0); // 开始播放静音
- break;
- default:
- break;
- }
- return 0;
- }
- int video_stream_component_open(VideoState *is, int stream_index) {
- AVFormatContext *pFormatCtx = is->ic;
- AVCodecContext *codecCtx;
- AVCodec *codec;
- if (stream_index < 0 || stream_index >= pFormatCtx->nb_streams) {
- return -1;
- }
- // Get a pointer to the codec context for the video stream
- codecCtx = pFormatCtx->streams[stream_index]->codec;
- codec = avcodec_find_decoder(codecCtx->codec_id);
- if (!codec || (avcodec_open2(codecCtx, codec, NULL) < 0)) {
- fprintf(stderr, "Unsupported codec!\n");
- return -1;
- }
- switch (codecCtx->codec_type) {
- case AVMEDIA_TYPE_VIDEO:
- is->videoStream = stream_index;
- is->video_st = pFormatCtx->streams[stream_index];
- is->sws_ctx = sws_getContext(is->video_st->codec->width,
- is->video_st->codec->height, is->video_st->codec->pix_fmt,
- is->video_st->codec->width, is->video_st->codec->height,
- AV_PIX_FMT_YUV420P, SWS_FAST_BILINEAR, NULL, NULL, NULL);
- 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_tid = SDL_CreateThread(video_thread, "video_thread", is);
- codecCtx->get_buffer = our_get_buffer;
- codecCtx->release_buffer = our_release_buffer;
- break;
- default:
- break;
- }
- return 0;
- }
- int decode_thread(void *arg) {
- VideoState *is = (VideoState *) arg;
- AVFormatContext *pFormatCtx = NULL;
- AVPacket pkt1, *packet = &pkt1;
- int video_index = -1;
- int audio_index = -1;
- int i;
- is->videoStream = -1;
- is->audioStream = -1;
- AVIOInterruptCB interupt_cb;
- global_video_state = is;
- // will interrup blocking functions if we quit!
- interupt_cb.callback = decode_interrupt_cb;
- interupt_cb.opaque = is;
- if (avio_open2(&is->io_ctx, is->filename, 0, &interupt_cb, NULL)) {
- fprintf(stderr, "Cannot open I/O for %s\n", is->filename);
- return -1;
- }
- //Open video file
- if (avformat_open_input(&pFormatCtx, is->filename, NULL, NULL) != 0) {
- return -1; //Couldn't open file
- }
- is->ic = pFormatCtx;
- //Retrieve stream infomation
- 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->coder_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) {
- /* 所有设置SDL音频流信息的步骤都在这个函数里完成 */
- audio_stream_component_open(is, audio_index);
- }
- if (video_index >= 0) {
- video_stream_component_open(is, video_index);
- }
- if (is->videoStream < 0 || is->audioStream <= 0) {
- fprintf(stderr, "%s: could not open codec\n", is->filename);
- goto fail;
- }
- //main decode loop
- /* 读包的主循环, av_read_frame不停的从文件中读取数据包*/
- for (;;) {
- if (is->quit) {
- break;
- }
- //seek stuff goes here
- /* 这里audioq.size是指队列中的所有数据包带的音频数据的总量或者视频数据总量,并不是包的数量 */
- if (is->audioq.size > MAX_AUDIOQ_SIZE || is->videoq.size > MAX_VIDEOQ_SIZE) {
- SDL_Delay(10);
- continue;
- }
- if (av_read_frame(is->ic, packet) < 0) {
- if (is->ic->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[]) {
- char *filename = argv[1];
- SDL_Event event;
- VideoState *is;
- is = av_malloc(sizeof(VideoState));
- // 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);
- }
- av_strlcpy(is->filename, filename, 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(decode_thread, "parse_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:
- SDL_CondSignal(is->audioq.cond);
- SDL_CondSignal(is->videoq.cond);
- is->quit = 1;
- SDL_Quit();
- return 0;
- break;
- case FF_ALLOC_EVENT:
- alloc_picture(event.user.data1);
- break;
- case FF_REFRESH_EVENT:
- video_refresh_timer(event.user.data1);
- break;
- }
- }
- return 0;
- }
- 顶
- 0
- 踩
阅读全文
0 0
- 如何在Android用FFmpeg+SDL2.0之同步音频
- 如何在Android用FFmpeg+SDL2.0之同步音频
- 如何在Android用FFmpeg+SDL2.0之同步视频
- 如何在Android用FFmpeg+SDL2.0解码显示图像
- 如何在Android用FFmpeg+SDL2.0解码声音
- 如何在Android用FFmpeg+SDL2.0解码图像线程
- ffmpeg SDL2.0播放音频
- ffmpeg(3):ffmpeg结合SDL2.0解码音频流
- ffmpeg (三):ffmpeg结合SDL2.0解码音频流
- ffmpeg+sdl2.0做一个简单的音频播放器
- ffmpeg+sdl2.0做一个简单的音频播放器
- [6] ffmpeg + SDL2 实现的视频播放器「视音频同步」
- ffmpeg + SDL2 实现的视频播放器「视音频同步」
- ffmpeg + SDL2 实现的视频播放器「视音频同步」
- Ffmpeg和SDL如何同步音频
- ffmpeg and SDL2.0
- ffmpeg学习---7.音视频同步之视频同步音频
- FFmpeg:视音频同步
- 关于闭包一点浅见
- openGL-边界填充
- Linux 压缩文件 zip
- 片上系统(计算机)所涉及的硬件资源(RAM ROM SRAM DRAM FLASH... ...)
- 抽象工厂模式
- 如何在Android用FFmpeg+SDL2.0之同步音频
- 计算机视觉、机器学习相关领域论文和源代码大集合
- Detecting and Recognizing Human-Object Interactions
- 学习vue框架(二)
- 高精度之高精度乘法
- Mask R-CNN
- 人工智能、机器学习与深度学习
- 【TensorFlow】tf.scatter_update()
- C++/MFC-时间与日期