[FFmpeg-cvslog] udp: add a thread into udp.c for receiving data into a circular buffer, this stops the problem of live decoding/encoding giving errors.
JULIAN GARDNER
git at videolan.org
Fri May 13 17:56:06 CEST 2011
ffmpeg | branch: master | JULIAN GARDNER <joolzg at btinternet.com> | Fri May 13 16:28:42 2011 +0200| [4275602183d35eed9a9b7bbfef57ffc44d3484e7] | committer: Michael Niedermayer
udp: add a thread into udp.c for receiving data into a circular buffer, this stops the problem of live decoding/encoding giving errors.
Also added a buf_size which is the number of TS packets that to be allocated for the circular buffer.
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=4275602183d35eed9a9b7bbfef57ffc44d3484e7
---
libavformat/udp.c | 156 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
1 files changed, 155 insertions(+), 1 deletions(-)
diff --git a/libavformat/udp.c b/libavformat/udp.c
index 35c1774..6f3b801 100644
--- a/libavformat/udp.c
+++ b/libavformat/udp.c
@@ -34,6 +34,9 @@
#include "network.h"
#include "os_support.h"
#include "url.h"
+#include <pthread.h>
+#include <semaphore.h>
+#include <sys/resource.h>
#include <sys/time.h>
#ifndef IPV6_ADD_MEMBERSHIP
@@ -51,8 +54,22 @@ typedef struct {
struct sockaddr_storage dest_addr;
int dest_addr_len;
int is_connected;
+
+ /* Circular Buffer variables for use in UDP receive code */
+ unsigned char *circular_buffer;
+ int circular_buffer_head;
+ int circular_buffer_size;
+ int circular_buffer_tail;
+ int circular_buffer_available;
+ int circular_buffer_available_max;
+ int circular_buffer_error;
+ pthread_t circular_buffer_thread;
+ sem_t circular_buffer_semaphore;
} UDPContext;
+#define min(X,Y) ((X)<(Y) ? (X):(Y))
+#define max(X,Y) ((X)>(Y) ? (X):(Y))
+
#define UDP_TX_BUF_SIZE 32768
#define UDP_MAX_PKT_SIZE 65536
@@ -298,6 +315,69 @@ static int udp_get_file_handle(URLContext *h)
return s->udp_fd;
}
+static void *circular_buffer_task( void *_URLContext)
+{
+ URLContext *h = _URLContext;
+ UDPContext *s = h->priv_data;
+ fd_set rfds;
+ struct timeval tv;
+
+ for(;;) {
+ int left;
+ int ret;
+ int len;
+
+ if (url_interrupt_cb()) {
+ s->circular_buffer_error = EINTR;
+ return NULL;
+ }
+
+ FD_ZERO(&rfds);
+ FD_SET(s->udp_fd, &rfds);
+ tv.tv_sec = 1;
+ tv.tv_usec = 0;
+ ret = select(s->udp_fd + 1, &rfds, NULL, NULL, &tv);
+ if (ret < 0) {
+ if (ff_neterrno() == AVERROR(EINTR))
+ continue;
+ s->circular_buffer_error = EIO;
+ return NULL;
+ }
+
+ if (!(ret > 0 && FD_ISSET(s->udp_fd, &rfds)))
+ continue;
+
+ /* How much do we have left to the end of the buffer */
+ left = s->circular_buffer_size-s->circular_buffer_head;
+ /* Whats the minimum we can read so that we dont comletely fill the buffer */
+ sem_wait( &s->circular_buffer_semaphore);
+ left = min( left, s->circular_buffer_size-s->circular_buffer_available);
+ sem_post( &s->circular_buffer_semaphore );
+ /* No Space left, error, what do we do now */
+ if( !left) {
+ av_log(h, AV_LOG_ERROR, "circular_buffer: OVERRUN\n");
+ s->circular_buffer_error = EIO;
+ return NULL;
+ }
+ len = recv(s->udp_fd, s->circular_buffer+s->circular_buffer_head, left, 0);
+ if (len < 0) {
+ if (ff_neterrno() != AVERROR(EAGAIN) && ff_neterrno() != AVERROR(EINTR)) {
+ s->circular_buffer_error = EIO;
+ return NULL;
+ }
+ }
+ s->circular_buffer_head += len;
+ sem_wait( &s->circular_buffer_semaphore);
+ s->circular_buffer_available += len;
+ s->circular_buffer_available_max = max( s->circular_buffer_available_max, s->circular_buffer_available);
+ sem_post( &s->circular_buffer_semaphore );
+ if( s->circular_buffer_head>=s->circular_buffer_size)
+ s->circular_buffer_head -= s->circular_buffer_size;
+ }
+
+ return NULL;
+}
+
/* put it in UDP context */
/* return non zero if error */
static int udp_open(URLContext *h, const char *uri, int flags)
@@ -325,10 +405,12 @@ static int udp_open(URLContext *h, const char *uri, int flags)
s->ttl = 16;
s->buffer_size = is_output ? UDP_TX_BUF_SIZE : UDP_MAX_PKT_SIZE;
+ s->circular_buffer_size = 7*188*4096;
+
p = strchr(uri, '?');
if (p) {
if (av_find_info_tag(buf, sizeof(buf), "reuse", p)) {
- const char *endptr=NULL;
+ char *endptr=NULL;
s->reuse_socket = strtol(buf, &endptr, 10);
/* assume if no digits were found it is a request to enable it */
if (buf == endptr)
@@ -350,6 +432,9 @@ static int udp_open(URLContext *h, const char *uri, int flags)
if (av_find_info_tag(buf, sizeof(buf), "connect", p)) {
s->is_connected = strtol(buf, NULL, 10);
}
+ if (av_find_info_tag(buf, sizeof(buf), "buf_size", p)) {
+ s->circular_buffer_size = strtol(buf, NULL, 10)*188;
+ }
}
/* fill the dest addr */
@@ -431,10 +516,28 @@ static int udp_open(URLContext *h, const char *uri, int flags)
}
s->udp_fd = udp_fd;
+
+ if (!is_output && s->circular_buffer_size) {
+ /* start the task going */
+ s->circular_buffer = av_malloc( s->circular_buffer_size);
+ if (sem_init( &s->circular_buffer_semaphore, PTHREAD_PROCESS_PRIVATE, 1 )) {
+ av_log(h, AV_LOG_ERROR, "sem_init failed\n");
+ goto fail;
+ }
+ if (pthread_create(&s->circular_buffer_thread, NULL, circular_buffer_task, h)) {
+ av_log(h, AV_LOG_ERROR, "pthread_create failed\n");
+ goto fail;
+ }
+ }
+
return 0;
fail:
if (udp_fd >= 0)
closesocket(udp_fd);
+ if (s->circular_buffer) {
+ sem_destroy( &s->circular_buffer_semaphore);
+ av_free( s->circular_buffer);
+ }
av_free(s);
return AVERROR(EIO);
}
@@ -443,6 +546,51 @@ static int udp_read(URLContext *h, uint8_t *buf, int size)
{
UDPContext *s = h->priv_data;
int ret;
+ int avail;
+ int left;
+ fd_set rfds;
+ struct timeval tv;
+
+ if (s->circular_buffer_thread) {
+
+ do {
+ sem_wait( &s->circular_buffer_semaphore );
+ avail = s->circular_buffer_available;
+ sem_post( &s->circular_buffer_semaphore );
+ if (avail) { // >=size) {
+
+ // Maximum amount available
+ size = min( avail, size);
+ // Whats left till the end of the circular buffer
+ left = s->circular_buffer_size-s->circular_buffer_tail;
+ // How much do we need, all?
+ left = min( left, size);
+ // Get the first block
+ memcpy( buf, s->circular_buffer+s->circular_buffer_tail, left);
+ // Have we any more, this will be from the start of the buffer
+ if (size-left)
+ memcpy( buf+left, s->circular_buffer, size-left);
+ // Check for the tail wrapping around
+ s->circular_buffer_tail += size;
+ if( s->circular_buffer_tail>=s->circular_buffer_size)
+ s->circular_buffer_tail -= s->circular_buffer_size;
+ // Update the available amount
+ sem_wait( &s->circular_buffer_semaphore );
+ s->circular_buffer_available -= size;
+ sem_post( &s->circular_buffer_semaphore );
+ return size;
+ }
+ else {
+ FD_ZERO(&rfds);
+ FD_SET(s->udp_fd, &rfds);
+ tv.tv_sec = 1;
+ tv.tv_usec = 0;
+ ret = select(s->udp_fd + 1, &rfds, NULL, NULL, &tv);
+ if (ret<0)
+ return ret;
+ }
+ } while( 1);
+ }
if (!(h->flags & AVIO_FLAG_NONBLOCK)) {
ret = ff_network_wait_fd(s->udp_fd, 0);
@@ -450,6 +598,7 @@ static int udp_read(URLContext *h, uint8_t *buf, int size)
return ret;
}
ret = recv(s->udp_fd, buf, size, 0);
+
return ret < 0 ? ff_neterrno() : ret;
}
@@ -481,6 +630,11 @@ static int udp_close(URLContext *h)
if (s->is_multicast && (h->flags & AVIO_FLAG_READ))
udp_leave_multicast_group(s->udp_fd, (struct sockaddr *)&s->dest_addr);
closesocket(s->udp_fd);
+ if (s->circular_buffer) {
+ sem_destroy( &s->circular_buffer_semaphore);
+ av_free( s->circular_buffer);
+ av_log( h, AV_LOG_INFO, "circular_buffer_info max:%d%%\r\n", (s->circular_buffer_available_max*100)/s->circular_buffer_size);
+ }
av_free(s);
return 0;
}
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