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zero copy packet handling for DV1394 by Max Krasnyansky

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Originally committed as revision 1542 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Fabrice Bellard 2003-02-03 22:58:29 +00:00
parent cdc90af008
commit 6fa5a56c1b
3 changed files with 79 additions and 59 deletions
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30
libavformat/avformat.h
View File

@ -20,15 +20,33 @@ extern "C" {
typedef struct AVPacket {
INT64 pts; /* presentation time stamp in stream units (set av_set_pts_info) */
UINT8 *data;
int size;
int stream_index;
int flags;
int duration;
#define PKT_FLAG_KEY 0x0001
int size;
int stream_index;
int flags;
int duration;
void (*destruct)(struct AVPacket *);
void *priv;
} AVPacket;
#define PKT_FLAG_KEY 0x0001
static inline void av_init_packet(AVPacket *pkt)
{
pkt->pts = AV_NOPTS_VALUE;
pkt->flags = 0;
pkt->stream_index = 0;
}
int av_new_packet(AVPacket *pkt, int size);
void av_free_packet(AVPacket *pkt);
/**
* Free a packet
*
* @param pkt packet to free
*/
static inline void av_free_packet(AVPacket *pkt)
{
pkt->destruct(pkt);
}
/*************************************************/
/* fractional numbers for exact pts handling */

69
libavformat/dv1394.c
View File

@ -19,6 +19,7 @@
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <sys/poll.h>
@ -60,7 +61,8 @@ static int dv1394_reset(struct dv1394_data *dv)
if (ioctl(dv->fd, DV1394_INIT, &init) < 0)
return -1;
dv->avail = 0;
dv->avail = dv->done = 0;
dv->stream = 0;
return 0;
}
@ -85,7 +87,7 @@ static int dv1394_read_header(AVFormatContext * context, AVFormatParameters * ap
return -ENOMEM;
ast = av_new_stream(context, 1);
if (!ast) {
av_free(vst);
av_free(vst);
return -ENOMEM;
}
@ -158,7 +160,13 @@ failed:
return -EIO;
}
static inline int __copy_frame(struct dv1394_data *dv, AVPacket *pkt)
static void __destruct_pkt(struct AVPacket *pkt)
{
pkt->data = NULL; pkt->size = 0;
return;
}
static inline int __get_frame(struct dv1394_data *dv, AVPacket *pkt)
{
char *ptr = dv->ring + (dv->index * dv->frame_size);
@ -166,12 +174,15 @@ static inline int __copy_frame(struct dv1394_data *dv, AVPacket *pkt)
dv->index = (dv->index + 1) % DV1394_RING_FRAMES;
dv->done++; dv->avail--;
} else {
dv->pts = av_gettime() & ((1LL << 48) - 1);
dv->pts = av_gettime() & ((1LL << 48) - 1);
}
memcpy(pkt->data, ptr, dv->frame_size);
av_init_packet(pkt);
pkt->destruct = __destruct_pkt;
pkt->data = ptr;
pkt->size = dv->frame_size;
pkt->pts = dv->pts;
pkt->stream_index = dv->stream;
pkt->pts = dv->pts;
dv->stream ^= 1;
@ -181,16 +192,33 @@ static inline int __copy_frame(struct dv1394_data *dv, AVPacket *pkt)
static int dv1394_read_packet(AVFormatContext *context, AVPacket *pkt)
{
struct dv1394_data *dv = context->priv_data;
int len;
if (!dv->avail) {
struct dv1394_status s;
struct pollfd p;
p.fd = dv->fd;
p.events = POLLIN | POLLERR | POLLHUP;
if (dv->done) {
/* Request more frames */
if (ioctl(dv->fd, DV1394_RECEIVE_FRAMES, dv->done) < 0) {
/* This usually means that ring buffer overflowed.
* We have to reset :(.
*/
fprintf(stderr, "DV1394: Ring buffer overflow. Reseting ..\n");
dv1394_reset(dv);
dv1394_start(dv);
}
dv->done = 0;
}
/* Wait until more frames are available */
restart_poll:
p.fd = dv->fd;
p.events = POLLIN | POLLERR | POLLHUP;
if (poll(&p, 1, -1) < 0) {
if (errno == EAGAIN || errno == EINTR)
goto restart_poll;
perror("Poll failed");
return -EIO;
}
@ -211,7 +239,7 @@ static int dv1394_read_packet(AVFormatContext *context, AVPacket *pkt)
dv->avail = s.n_clear_frames;
dv->index = s.first_clear_frame;
dv->done = 0;
dv->done = 0;
if (s.dropped_frames) {
fprintf(stderr, "DV1394: Frame drop detected (%d). Reseting ..\n",
@ -222,31 +250,12 @@ static int dv1394_read_packet(AVFormatContext *context, AVPacket *pkt)
}
}
if (av_new_packet(pkt, dv->frame_size) < 0)
return -EIO;
#ifdef DV1394_DEBUG
fprintf(stderr, "index %d, avail %d, done %d\n", dv->index, dv->avail,
dv->done);
#endif
len = __copy_frame(dv, pkt);
if (!dv->avail && dv->done) {
/* Request more frames */
if (ioctl(dv->fd, DV1394_RECEIVE_FRAMES, dv->done) < 0) {
/* This usually means that ring buffer overflowed.
* We have to reset :(.
*/
fprintf(stderr, "DV1394: Ring buffer overflow. Reseting ..\n");
dv1394_reset(dv);
dv1394_start(dv);
}
}
return len;
return __get_frame(dv, pkt);
}
static int dv1394_close(AVFormatContext * context)

39
libavformat/utils.c
View File

@ -150,6 +150,15 @@ AVInputFormat *av_find_input_format(const char *short_name)
/* memory handling */
/**
* Default packet destructor
*/
static void av_destruct_packet(AVPacket *pkt)
{
av_free(pkt->data);
pkt->data = NULL; pkt->size = 0;
}
/**
* Allocate the payload of a packet and intialized its fields to default values.
*
@ -159,34 +168,18 @@ AVInputFormat *av_find_input_format(const char *short_name)
*/
int av_new_packet(AVPacket *pkt, int size)
{
int i;
pkt->data = av_malloc(size + FF_INPUT_BUFFER_PADDING_SIZE);
if (!pkt->data)
void *data = av_malloc(size + FF_INPUT_BUFFER_PADDING_SIZE);
if (!data)
return AVERROR_NOMEM;
memset(data + size, 0, FF_INPUT_BUFFER_PADDING_SIZE);
av_init_packet(pkt);
pkt->data = data;
pkt->size = size;
/* sane state */
pkt->pts = AV_NOPTS_VALUE;
pkt->stream_index = 0;
pkt->flags = 0;
for(i=0; i<FF_INPUT_BUFFER_PADDING_SIZE; i++)
pkt->data[size+i]= 0;
pkt->destruct = av_destruct_packet;
return 0;
}
/**
* Free a packet
*
* @param pkt packet to free
*/
void av_free_packet(AVPacket *pkt)
{
av_freep(&pkt->data);
/* fail safe */
pkt->size = 0;
}
/* fifo handling */
int fifo_init(FifoBuffer *f, int size)