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correct small framerate fluctuations directly in the capture thread

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git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@9608 b3059339-0415-0410-9bf9-f77b7e298cf2
This commit is contained in:
henry
2003-03-15 22:02:54 +00:00
parent 0b38aaf6ec
commit 62b166e62d
1 changed files with 47 additions and 1 deletions
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libmpdemux/tvi_v4l.c
+47 -1
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@@ -60,6 +60,7 @@ static tvi_info_t info = {
#define MAX_AUDIO_CHANNELS 10
#define VID_BUF_SIZE_IMMEDIATE 2
#define VIDEO_AVG_BUFFER_SIZE 300
typedef struct {
/* general */
@@ -111,6 +112,9 @@ typedef struct {
volatile int video_buffer_size_current;
unsigned char **video_ringbuffer;
long long *video_timebuffer;
long long *video_avg_buffer;
int video_avg_ptr;
int video_interval_sum;
volatile int video_head;
volatile int video_tail;
volatile int video_cnt;
@@ -404,6 +408,7 @@ static int init(priv_t *priv)
priv->video_ringbuffer = NULL;
priv->video_timebuffer = NULL;
priv->video_avg_buffer = NULL;
priv->audio_ringbuffer = NULL;
priv->audio_skew_buffer = NULL;
@@ -582,6 +587,8 @@ static int uninit(priv_t *priv)
if (priv->video_timebuffer)
free(priv->video_timebuffer);
if (priv->video_avg_buffer)
free(priv->video_avg_buffer);
if (!tv_param_noaudio) {
if (priv->audio_ringbuffer)
free(priv->audio_ringbuffer);
@@ -762,6 +769,18 @@ static int start(priv_t *priv)
mp_msg(MSGT_TV, MSGL_ERR, "cannot allocate time buffer: %s\n", strerror(errno));
return 0;
}
priv->video_avg_buffer = (long long*)malloc(sizeof(long long) * VIDEO_AVG_BUFFER_SIZE);
if (!priv->video_avg_buffer) {
mp_msg(MSGT_TV, MSGL_ERR, "cannot allocate period buffer: %s\n", strerror(errno));
return 0;
}
priv->video_interval_sum = (1e6/priv->fps)*VIDEO_AVG_BUFFER_SIZE;
for (i = 0; i < VIDEO_AVG_BUFFER_SIZE; i++) {
priv->video_avg_buffer[i] = 1e6/priv->fps;
}
priv->video_avg_ptr = 0;
priv->video_head = 0;
priv->video_tail = 0;
priv->video_cnt = 0;
@@ -1243,6 +1262,7 @@ static void *video_grabber(void *data)
int i;
int first = 1;
int framecount;
int tolerance;
/* start the capture process */
@@ -1256,6 +1276,8 @@ static void *video_grabber(void *data)
prev_interval = 0;
prev_skew = 0;
tolerance = priv->nbuf*2;
for (framecount = 0; !priv->shutdown;)
{
for (i = 0; i < priv->nbuf && !priv->shutdown; i++, framecount++) {
@@ -1302,6 +1324,25 @@ static void *video_grabber(void *data)
mp_msg(MSGT_TV, MSGL_V, "\nvideo capture thread: frame delta ~ %.1lf fps\n",
(double)1e6/(interval - prev_interval));
}
// correct the rate fluctuations on a small scale
if ((interval - prev_interval < (long long)0.95e6/priv->fps)
|| (interval - prev_interval > (long long)1.05e6/priv->fps) ) {
if (tolerance > 0) {
mp_msg(MSGT_TV, MSGL_DBG3, "correcting timestamp\n");
interval = prev_interval + priv->video_interval_sum/VIDEO_AVG_BUFFER_SIZE;
tolerance--;
} else {
mp_msg(MSGT_TV, MSGL_DBG3, "bad - frames were dropped\n");
tolerance = priv->nbuf*2;
}
} else {
if (tolerance < priv->nbuf*2) {
mp_msg(MSGT_TV, MSGL_DBG3, "fluctuation overcome\n");
}
tolerance = priv->nbuf*2;
}
}
// interpolate the skew in time
@@ -1323,9 +1364,14 @@ static void *video_grabber(void *data)
(double)1e-6*interval, (double)1e-6*xskew, (double)1e-6*skew);
mp_msg(MSGT_TV, MSGL_DBG3, "vcnt = %d, acnt = %d\n", priv->video_cnt, priv->audio_cnt);
priv->video_interval_sum -= priv->video_avg_buffer[priv->video_avg_ptr];
priv->video_avg_buffer[priv->video_avg_ptr++] = interval-prev_interval;
priv->video_interval_sum += interval-prev_interval;
if (priv->video_avg_ptr >= VIDEO_AVG_BUFFER_SIZE) priv->video_avg_ptr = 0;
prev_skew = skew;
prev_interval = interval;
/* allocate a new buffer, if needed */
pthread_mutex_lock(&priv->video_buffer_mutex);
if (priv->video_buffer_size_current < priv->video_buffer_size_max) {