Commit 638c9d91 authored by Fabrice Bellard's avatar Fabrice Bellard
Browse files

fine A-V synchronisation support with either audio or video as master clock...

fine A-V synchronisation support with either audio or video as master clock source - MPEG2 A-V synchronisation fixes - fixed format selection - fixed error reporting - audio and video component selection

Originally committed as revision 2106 to svn://svn.ffmpeg.org/ffmpeg/trunk
parent 1fbe1a61
......@@ -37,9 +37,26 @@
#include <X11/Xlib.h>
#endif
//#define DEBUG_SYNC
#define MAX_VIDEOQ_SIZE (5 * 256 * 1024)
#define MAX_AUDIOQ_SIZE (5 * 16 * 1024)
/* SDL audio buffer size, in samples. Should be small to have precise
A/V sync as SDL does not have hardware buffer fullness info. */
#define SDL_AUDIO_BUFFER_SIZE 1024
/* no AV sync correction is done if below the AV sync threshold */
#define AV_SYNC_THRESHOLD 0.08
/* no AV correction is done if too big error */
#define AV_NOSYNC_THRESHOLD 10.0
/* maximum audio speed change to get correct sync */
#define SAMPLE_CORRECTION_PERCENT_MAX 10
/* we use about AUDIO_DIFF_AVG_NB A-V differences to make the average */
#define AUDIO_DIFF_AVG_NB 20
/* NOTE: the size must be big enough to compensate the hardware audio buffersize size */
#define SAMPLE_ARRAY_SIZE (2*65536)
......@@ -55,7 +72,7 @@ typedef struct PacketQueue {
#define VIDEO_PICTURE_QUEUE_SIZE 1
typedef struct VideoPicture {
int delay; /* delay before showing the next picture */
double pts; /* presentation time stamp for this picture */
SDL_Overlay *bmp;
int width, height; /* source height & width */
int allocated;
......@@ -64,12 +81,13 @@ typedef struct VideoPicture {
enum {
AV_SYNC_AUDIO_MASTER, /* default choice */
AV_SYNC_VIDEO_MASTER,
AV_SYNC_EXTERNAL_CLOCK, /* if external clock, then you must update external_clock yourself */
AV_SYNC_EXTERNAL_CLOCK, /* synchronize to an external clock */
};
typedef struct VideoState {
SDL_Thread *parse_tid;
SDL_Thread *video_tid;
AVInputFormat *iformat;
int no_background;
int abort_request;
int paused;
......@@ -80,9 +98,14 @@ typedef struct VideoState {
int audio_stream;
int av_sync_type;
double external_clock; /* external clock */
double audio_clock; /* current audio clock value */
double external_clock; /* external clock base */
int64_t external_clock_time;
double audio_clock;
double audio_diff_cum; /* used for AV difference average computation */
double audio_diff_avg_coef;
double audio_diff_threshold;
int audio_diff_avg_count;
AVStream *audio_st;
PacketQueue audioq;
int audio_hw_buf_size;
......@@ -101,11 +124,22 @@ typedef struct VideoState {
int sample_array_index;
int last_i_start;
double video_clock; /* current video clock value */
double frame_timer;
double frame_last_pts;
double frame_last_delay;
double video_clock;
int video_stream;
AVStream *video_st;
PacketQueue videoq;
int64_t ipts;
int picture_start; /* true if picture starts */
double video_last_P_pts; /* pts of the last P picture (needed if B
frames are present) */
double video_current_pts; /* current displayed pts (different from
video_clock if frame fifos are used) */
int64_t video_current_pts_time; /* time at which we updated
video_current_pts - used to
have running video pts */
VideoPicture pictq[VIDEO_PICTURE_QUEUE_SIZE];
int pictq_size, pictq_rindex, pictq_windex;
SDL_mutex *pictq_mutex;
......@@ -117,7 +151,7 @@ typedef struct VideoState {
} VideoState;
void show_help(void);
int audio_write_get_buf_size(VideoState *is);
static int audio_write_get_buf_size(VideoState *is);
/* options specified by the user */
static AVInputFormat *file_iformat;
......@@ -130,6 +164,7 @@ static int audio_disable;
static int video_disable;
static int display_disable;
static int show_status;
static int av_sync_type = AV_SYNC_AUDIO_MASTER;
/* current context */
static int is_full_screen;
......@@ -138,6 +173,7 @@ static int64_t audio_callback_time;
#define FF_ALLOC_EVENT (SDL_USEREVENT)
#define FF_REFRESH_EVENT (SDL_USEREVENT + 1)
#define FF_QUIT_EVENT (SDL_USEREVENT + 2)
SDL_Surface *screen;
......@@ -467,21 +503,119 @@ static void schedule_refresh(VideoState *is, int delay)
SDL_AddTimer(delay, sdl_refresh_timer_cb, is);
}
/* get the current audio clock value */
static double get_audio_clock(VideoState *is)
{
double pts;
int hw_buf_size, bytes_per_sec;
pts = is->audio_clock;
hw_buf_size = audio_write_get_buf_size(is);
bytes_per_sec = 0;
if (is->audio_st) {
bytes_per_sec = is->audio_st->codec.sample_rate *
2 * is->audio_st->codec.channels;
}
if (bytes_per_sec)
pts -= (double)hw_buf_size / bytes_per_sec;
return pts;
}
/* get the current video clock value */
static double get_video_clock(VideoState *is)
{
double delta;
delta = (av_gettime() - is->video_current_pts_time) / 1000000.0;
return is->video_current_pts + delta;
}
/* get the current external clock value */
static double get_external_clock(VideoState *is)
{
int64_t ti;
ti = av_gettime();
return is->external_clock + ((ti - is->external_clock_time) * 1e-6);
}
/* get the current master clock value */
static double get_master_clock(VideoState *is)
{
double val;
if (is->av_sync_type == AV_SYNC_VIDEO_MASTER && is->video_st)
val = get_video_clock(is);
else if (is->av_sync_type == AV_SYNC_AUDIO_MASTER && is->audio_st)
val = get_audio_clock(is);
else
val = get_external_clock(is);
return val;
}
/* called to display each frame */
static void video_refresh_timer(void *opaque)
{
VideoState *is = opaque;
VideoPicture *vp;
double actual_delay, delay, sync_threshold, ref_clock, diff;
if (is->video_st) {
if (is->pictq_size == 0) {
/* if no picture, need to wait */
schedule_refresh(is, 40);
} else {
/* dequeue the picture */
vp = &is->pictq[is->pictq_rindex];
/* update current video pts */
is->video_current_pts = vp->pts;
is->video_current_pts_time = av_gettime();
/* compute nominal delay */
delay = vp->pts - is->frame_last_pts;
if (delay <= 0 || delay >= 1.0) {
/* if incorrect delay, use previous one */
delay = is->frame_last_delay;
}
is->frame_last_delay = delay;
is->frame_last_pts = vp->pts;
/* update delay to follow master synchronisation source */
if (((is->av_sync_type == AV_SYNC_AUDIO_MASTER && is->audio_st) ||
is->av_sync_type == AV_SYNC_EXTERNAL_CLOCK)) {
/* if video is slave, we try to correct big delays by
duplicating or deleting a frame */
ref_clock = get_master_clock(is);
diff = vp->pts - ref_clock;
/* skip or repeat frame. We take into account the
delay to compute the threshold. I still don't know
if it is the best guess */
sync_threshold = AV_SYNC_THRESHOLD;
if (delay > sync_threshold)
sync_threshold = delay;
if (fabs(diff) < AV_NOSYNC_THRESHOLD) {
if (diff <= -sync_threshold)
delay = 0;
else if (diff >= sync_threshold)
delay = 2 * delay;
}
}
is->frame_timer += delay;
/* compute the REAL delay (we need to do that to avoid
long term errors */
actual_delay = is->frame_timer - (av_gettime() / 1000000.0);
if (actual_delay < 0.010) {
/* XXX: should skip picture */
actual_delay = 0.010;
}
/* launch timer for next picture */
schedule_refresh(is, vp->delay);
schedule_refresh(is, (int)(actual_delay * 1000 + 0.5));
#if defined(DEBUG_SYNC)
printf("video: delay=%0.3f actual_delay=%0.3f pts=%0.3f A-V=%f\n",
delay, actual_delay, vp->pts, -diff);
#endif
/* display picture */
video_display(is);
......@@ -512,6 +646,7 @@ static void video_refresh_timer(void *opaque)
static int64_t last_time;
int64_t cur_time;
int aqsize, vqsize;
double av_diff;
cur_time = av_gettime();
if (!last_time || (cur_time - last_time) >= 500 * 1000) {
......@@ -521,8 +656,11 @@ static void video_refresh_timer(void *opaque)
aqsize = is->audioq.size;
if (is->video_st)
vqsize = is->videoq.size;
printf("A:%7.2f V:%7.2f aq=%5dKB vq=%5dKB \r",
is->audio_clock, is->video_clock, aqsize / 1024, vqsize / 1024);
av_diff = 0;
if (is->audio_st && is->video_st)
av_diff = get_audio_clock(is) - get_video_clock(is);
printf("%7.2f A-V:%7.3f aq=%5dKB vq=%5dKB \r",
get_master_clock(is), av_diff, aqsize / 1024, vqsize / 1024);
fflush(stdout);
last_time = cur_time;
}
......@@ -581,14 +719,11 @@ static void alloc_picture(void *opaque)
SDL_UnlockMutex(is->pictq_mutex);
}
#define VIDEO_CORRECTION_THRESHOLD 0.2
static int output_picture(VideoState *is, AVPicture *src_pict, double pts)
static int queue_picture(VideoState *is, AVFrame *src_frame, double pts)
{
VideoPicture *vp;
int dst_pix_fmt;
AVPicture pict;
double delay, ref_clock, diff;
/* wait until we have space to put a new picture */
SDL_LockMutex(is->pictq_mutex);
......@@ -628,6 +763,7 @@ static int output_picture(VideoState *is, AVPicture *src_pict, double pts)
return -1;
}
/* if the frame is not skipped, then display it */
if (vp->bmp) {
/* get a pointer on the bitmap */
SDL_LockYUVOverlay (vp->bmp);
......@@ -642,39 +778,12 @@ static int output_picture(VideoState *is, AVPicture *src_pict, double pts)
pict.linesize[2] = vp->bmp->pitches[1];
img_convert(&pict, dst_pix_fmt,
src_pict, is->video_st->codec.pix_fmt,
(AVPicture *)src_frame, is->video_st->codec.pix_fmt,
is->video_st->codec.width, is->video_st->codec.height);
/* update the bitmap content */
SDL_UnlockYUVOverlay(vp->bmp);
/* compute delay for the next frame and take into account the
pts if needed to make a correction. Since we do not support
correct MPEG B frame PTS, we put a high threshold */
if (is->av_sync_type == AV_SYNC_VIDEO_MASTER) {
ref_clock = is->video_clock;
} else if (is->av_sync_type == AV_SYNC_AUDIO_MASTER) {
/* cannot use audio master if no audio, so fall back to no sync */
if (!is->audio_st)
ref_clock = is->video_clock;
else
ref_clock = is->audio_clock;
} else {
ref_clock = is->external_clock;
}
diff = is->video_clock - ref_clock;
delay = (double)is->video_st->codec.frame_rate_base /
(double)is->video_st->codec.frame_rate;
if (fabs(diff) > VIDEO_CORRECTION_THRESHOLD) {
/* if too big difference, then we adjust */
delay += diff;
/* compute the difference */
if (delay < 0.01)
delay = 0.01;
else if (delay > 1.0)
delay = 1.0;
}
vp->delay = (int)(delay * 1000 + 0.5);
vp->pts = pts;
/* now we can update the picture count */
if (++is->pictq_windex == VIDEO_PICTURE_QUEUE_SIZE)
......@@ -683,15 +792,54 @@ static int output_picture(VideoState *is, AVPicture *src_pict, double pts)
is->pictq_size++;
SDL_UnlockMutex(is->pictq_mutex);
}
return 0;
}
/* compute the exact PTS for the picture if it is omitted in the stream */
static int output_picture2(VideoState *is, AVFrame *src_frame, double pts1)
{
double frame_delay, pts;
pts = pts1;
/* if B frames are present, and if the current picture is a I
or P frame, we use the last pts */
if (is->video_st->codec.has_b_frames &&
src_frame->pict_type != FF_B_TYPE) {
/* use last pts */
pts = is->video_last_P_pts;
/* get the pts for the next I or P frame if present */
is->video_last_P_pts = pts1;
}
/* update video clock */
if (pts != 0) {
/* update video clock with pts, if present */
is->video_clock = pts;
} else {
is->video_clock += (double)is->video_st->codec.frame_rate_base /
frame_delay = (double)is->video_st->codec.frame_rate_base /
(double)is->video_st->codec.frame_rate;
is->video_clock += frame_delay;
/* for MPEG2, the frame can be repeated, so we update the
clock accordingly */
if (src_frame->repeat_pict) {
is->video_clock += src_frame->repeat_pict * (frame_delay * 0.5);
}
}
return 0;
#if defined(DEBUG_SYNC) && 0
{
int ftype;
if (src_frame->pict_type == FF_B_TYPE)
ftype = 'B';
else if (src_frame->pict_type == FF_I_TYPE)
ftype = 'I';
else
ftype = 'P';
printf("frame_type=%c clock=%0.3f pts=%0.3f\n",
ftype, is->video_clock, pts1);
}
#endif
return queue_picture(is, src_frame, is->video_clock);
}
static int video_thread(void *arg)
......@@ -699,9 +847,8 @@ static int video_thread(void *arg)
VideoState *is = arg;
AVPacket pkt1, *pkt = &pkt1;
unsigned char *ptr;
int len, len1, got_picture, i;
int len, len1, got_picture;
AVFrame frame;
AVPicture pict;
int64_t ipts;
double pts;
......@@ -711,36 +858,40 @@ static int video_thread(void *arg)
}
if (packet_queue_get(&is->videoq, pkt, 1) < 0)
break;
/* NOTE: ipts is the PTS of the _first_ picture beginning in
this packet, if any */
ipts = pkt->pts;
ptr = pkt->data;
if (is->video_st->codec.codec_id == CODEC_ID_RAWVIDEO) {
avpicture_fill(&pict, ptr,
avpicture_fill((AVPicture *)&frame, ptr,
is->video_st->codec.pix_fmt,
is->video_st->codec.width,
is->video_st->codec.height);
pts = 0;
if (ipts != AV_NOPTS_VALUE)
pts = (double)ipts * is->ic->pts_num / is->ic->pts_den;
if (output_picture(is, &pict, pts) < 0)
frame.pict_type = FF_I_TYPE;
if (output_picture2(is, &frame, pts) < 0)
goto the_end;
} else {
len = pkt->size;
while (len > 0) {
if (is->picture_start) {
is->ipts = ipts;
is->picture_start = 0;
ipts = AV_NOPTS_VALUE;
}
len1 = avcodec_decode_video(&is->video_st->codec,
&frame, &got_picture, ptr, len);
if (len1 < 0)
break;
if (got_picture) {
for(i=0;i<4;i++) {
pict.data[i] = frame.data[i];
pict.linesize[i] = frame.linesize[i];
}
pts = 0;
if (ipts != AV_NOPTS_VALUE)
pts = (double)ipts * is->ic->pts_num / is->ic->pts_den;
ipts = AV_NOPTS_VALUE;
if (output_picture(is, &pict, pts) < 0)
if (is->ipts != AV_NOPTS_VALUE)
pts = (double)is->ipts * is->ic->pts_num / is->ic->pts_den;
if (output_picture2(is, &frame, pts) < 0)
goto the_end;
is->picture_start = 1;
}
ptr += len1;
len -= len1;
......@@ -773,74 +924,80 @@ static void update_sample_display(VideoState *is, short *samples, int samples_si
}
}
/* maximum audio speed change to get correct sync */
#define SAMPLE_CORRECTION_PERCENT_MAX 2
/* return the new audio buffer size (samples can be added or deleted
to get better sync if video or external master clock) */
static int synchronize_audio(VideoState *is, short *samples,
int samples_size, double pts)
int samples_size1, double pts)
{
int n, delay;
int n, samples_size;
double ref_clock;
n = 2 * is->audio_st->codec.channels;
samples_size = samples_size1;
if (is->av_sync_type == AV_SYNC_EXTERNAL_CLOCK)
ref_clock = is->external_clock;
else if (is->av_sync_type == AV_SYNC_VIDEO_MASTER && is->video_st)
ref_clock = is->video_clock;
else
ref_clock = is->audio_clock;
/* if not master, then we try to remove or add samples to correct the clock */
if (((is->av_sync_type == AV_SYNC_VIDEO_MASTER && is->video_st) ||
is->av_sync_type == AV_SYNC_EXTERNAL_CLOCK) && pts != 0) {
double diff;
is->av_sync_type == AV_SYNC_EXTERNAL_CLOCK)) {
double diff, avg_diff;
int wanted_size, min_size, max_size, nb_samples;
delay = audio_write_get_buf_size(is);
diff = pts - (double)delay / (double)(n * is->audio_st->codec.sample_rate) - ref_clock;
wanted_size = (int)(diff * is->audio_st->codec.sample_rate) * n;
nb_samples = samples_size / n;
min_size = ((nb_samples * (100 - SAMPLE_CORRECTION_PERCENT_MAX)) / 100) * n;
max_size = ((nb_samples * (100 + SAMPLE_CORRECTION_PERCENT_MAX)) / 100) * n;
if (wanted_size < min_size)
wanted_size = min_size;
else if (wanted_size > max_size)
wanted_size = max_size;
ref_clock = get_master_clock(is);
diff = get_audio_clock(is) - ref_clock;
/* do the correct */
/* XXX: do it better with sample interpolation */
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 */
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;
if (diff < AV_NOSYNC_THRESHOLD) {
is->audio_diff_cum = diff + is->audio_diff_avg_coef * is->audio_diff_cum;
if (is->audio_diff_avg_count < AUDIO_DIFF_AVG_NB) {
/* not enough measures to have a correct estimate */
is->audio_diff_avg_count++;
} else {
/* estimate the A-V difference */
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);
nb_samples = samples_size / n;
min_size = ((nb_samples * (100 - SAMPLE_CORRECTION_PERCENT_MAX)) / 100) * n;
max_size = ((nb_samples * (100 + SAMPLE_CORRECTION_PERCENT_MAX)) / 100) * n;
if (wanted_size < min_size)
wanted_size = min_size;
else if (wanted_size > max_size)
wanted_size = max_size;
/* add or remove samples to correction the synchro */
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 */
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;
}
}
#if 0
printf("diff=%f adiff=%f sample_diff=%d apts=%0.3f vpts=%0.3f %f\n",
diff, avg_diff, samples_size - samples_size1,
is->audio_clock, is->video_clock, is->audio_diff_threshold);
#endif
}
samples_size = wanted_size;
} else {
/* too big difference : may be initial PTS errors, so
reset A-V filter */
is->audio_diff_avg_count = 0;
is->audio_diff_cum = 0;
}
}
/* update audio clock */
if (is->av_sync_type == AV_SYNC_AUDIO_MASTER && pts != 0) {
/* a pts is given: we update the audio clock precisely */
delay = audio_write_get_buf_size(is);
is->audio_clock = pts - (double)delay / (double)(n * is->audio_st->codec.sample_rate);
} else {
is->audio_clock += (double)samples_size / (double)(n * is->audio_st->codec.sample_rate);
}
return samples_size;
}
......@@ -867,7 +1024,24 @@ static int audio_decode_frame(VideoState *is, uint8_t *audio_buf, double *pts_pt
pts = 0;
if (is->audio_pkt_ipts != AV_NOPTS_VALUE)
pts = (double)is->audio_pkt_ipts * is->ic->pts_num / is->ic->pts_den;
*pts_ptr = pts;
/* if no pts, then compute it */
if (pts != 0) {
is->audio_clock = pts;
} else {
int n;
n = 2 * is->audio_st->codec.channels;
is->audio_clock += (double)data_size / (double)(n * is->audio_st->codec.sample_rate);
}
#if defined(DEBUG_SYNC)
{
static double last_clock;
printf("audio: delay=%0.3f clock=%0.3f pts=%0.3f\n",
is->audio_clock - last_clock,
is->audio_clock, pts);
last_clock = is->audio_clock;
}
#endif
*pts_ptr = is->audio_clock;
is->audio_pkt_ipts = AV_NOPTS_VALUE;
/* we got samples : we can exit now */
return data_size;
......@@ -887,20 +1061,11 @@ static int audio_decode_frame(VideoState *is, uint8_t *audio_buf, double *pts_pt
}
}
int audio_write_get_buf_size(VideoState *is)
/* get the current audio output buffer size, in samples. With SDL, we
cannot have a precise information */
static int audio_write_get_buf_size(VideoState *is)
{
int delay;
delay = is->audio_hw_buf_size;
#if 0
/* just a test to check if the estimated delay is OK */
{
int val;
if (ioctl(sdl_audio_fd, SNDCTL_DSP_GETODELAY, &val) < 0)
perror("SNDCTL_DSP_GETODELAY");
printf("real_delay=%d delay=%d\n", val, delay);
}
#endif
return delay;
return is->audio_hw_buf_size - is->audio_buf_index;
}
......@@ -952,18 +1117,22 @@ static int stream_component_open(VideoState *is, int stream_ind