ffmpeg / libavformat / dv1394.c @ 5509bffa
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/*
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* Linux DV1394 interface
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* Copyright (c) 2003 Max Krasnyansky <maxk@qualcomm.com>
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include <unistd.h> |
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#include <fcntl.h> |
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#include <errno.h> |
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#include <sys/ioctl.h> |
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#include <sys/mman.h> |
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#include <sys/poll.h> |
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#include <sys/time.h> |
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#include <time.h> |
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#include "avformat.h" |
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#undef DV1394_DEBUG
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#include "dv1394.h" |
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#include "dv.h" |
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struct dv1394_data {
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int fd;
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int channel;
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int format;
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void *ring; /* Ring buffer */ |
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int index; /* Current frame index */ |
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int avail; /* Number of frames available for reading */ |
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int done; /* Number of completed frames */ |
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DVDemuxContext* dv_demux; /* Generic DV muxing/demuxing context */
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}; |
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/*
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* The trick here is to kludge around well known problem with kernel Ooopsing
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* when you try to capture PAL on a device node configure for NTSC. That's
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* why we have to configure the device node for PAL, and then read only NTSC
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* amount of data.
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*/
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static int dv1394_reset(struct dv1394_data *dv) |
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{ |
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struct dv1394_init init;
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init.channel = dv->channel; |
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init.api_version = DV1394_API_VERSION; |
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init.n_frames = DV1394_RING_FRAMES; |
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init.format = DV1394_PAL; |
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if (ioctl(dv->fd, DV1394_INIT, &init) < 0) |
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return -1; |
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dv->avail = dv->done = 0;
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return 0; |
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} |
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static int dv1394_start(struct dv1394_data *dv) |
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{ |
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/* Tell DV1394 driver to enable receiver */
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if (ioctl(dv->fd, DV1394_START_RECEIVE, 0) < 0) { |
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perror("Failed to start receiver");
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return -1; |
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} |
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return 0; |
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} |
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static int dv1394_read_header(AVFormatContext * context, AVFormatParameters * ap) |
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{ |
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struct dv1394_data *dv = context->priv_data;
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const char *video_device; |
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dv->dv_demux = dv_init_demux(context); |
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if (!dv->dv_demux)
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goto failed;
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if (ap->standard && !strcasecmp(ap->standard, "pal")) |
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dv->format = DV1394_PAL; |
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else
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dv->format = DV1394_NTSC; |
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if (ap->channel)
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dv->channel = ap->channel; |
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else
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dv->channel = DV1394_DEFAULT_CHANNEL; |
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/* Open and initialize DV1394 device */
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video_device = ap->device; |
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if (!video_device)
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video_device = "/dev/dv1394/0";
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dv->fd = open(video_device, O_RDONLY); |
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if (dv->fd < 0) { |
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perror("Failed to open DV interface");
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goto failed;
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} |
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if (dv1394_reset(dv) < 0) { |
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perror("Failed to initialize DV interface");
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goto failed;
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} |
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dv->ring = mmap(NULL, DV1394_PAL_FRAME_SIZE * DV1394_RING_FRAMES,
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PROT_READ, MAP_PRIVATE, dv->fd, 0);
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if (dv->ring == MAP_FAILED) {
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perror("Failed to mmap DV ring buffer");
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goto failed;
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} |
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if (dv1394_start(dv) < 0) |
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goto failed;
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return 0; |
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failed:
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close(dv->fd); |
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return AVERROR_IO;
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} |
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static int dv1394_read_packet(AVFormatContext *context, AVPacket *pkt) |
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{ |
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struct dv1394_data *dv = context->priv_data;
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int size;
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size = dv_get_packet(dv->dv_demux, pkt); |
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if (size > 0) |
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return size;
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if (!dv->avail) {
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struct dv1394_status s;
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struct pollfd p;
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if (dv->done) {
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/* Request more frames */
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if (ioctl(dv->fd, DV1394_RECEIVE_FRAMES, dv->done) < 0) { |
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/* This usually means that ring buffer overflowed.
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* We have to reset :(.
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*/
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av_log(context, AV_LOG_ERROR, "DV1394: Ring buffer overflow. Reseting ..\n");
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dv1394_reset(dv); |
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dv1394_start(dv); |
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} |
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dv->done = 0;
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} |
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/* Wait until more frames are available */
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restart_poll:
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p.fd = dv->fd; |
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p.events = POLLIN | POLLERR | POLLHUP; |
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if (poll(&p, 1, -1) < 0) { |
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if (errno == EAGAIN || errno == EINTR)
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goto restart_poll;
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perror("Poll failed");
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return AVERROR_IO;
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} |
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if (ioctl(dv->fd, DV1394_GET_STATUS, &s) < 0) { |
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perror("Failed to get status");
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return AVERROR_IO;
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} |
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#ifdef DV1394_DEBUG
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fprintf(stderr, "DV1394: status\n"
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"\tactive_frame\t%d\n"
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"\tfirst_clear_frame\t%d\n"
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"\tn_clear_frames\t%d\n"
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"\tdropped_frames\t%d\n",
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s.active_frame, s.first_clear_frame, |
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s.n_clear_frames, s.dropped_frames); |
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#endif
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dv->avail = s.n_clear_frames; |
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dv->index = s.first_clear_frame; |
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dv->done = 0;
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if (s.dropped_frames) {
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av_log(context, AV_LOG_ERROR, "DV1394: Frame drop detected (%d). Reseting ..\n",
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s.dropped_frames); |
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dv1394_reset(dv); |
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dv1394_start(dv); |
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} |
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} |
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#ifdef DV1394_DEBUG
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fprintf(stderr, "index %d, avail %d, done %d\n", dv->index, dv->avail,
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dv->done); |
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#endif
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size = dv_produce_packet(dv->dv_demux, pkt, |
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dv->ring + (dv->index * DV1394_PAL_FRAME_SIZE), |
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DV1394_PAL_FRAME_SIZE); |
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dv->index = (dv->index + 1) % DV1394_RING_FRAMES;
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dv->done++; dv->avail--; |
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return size;
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} |
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static int dv1394_close(AVFormatContext * context) |
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{ |
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struct dv1394_data *dv = context->priv_data;
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/* Shutdown DV1394 receiver */
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if (ioctl(dv->fd, DV1394_SHUTDOWN, 0) < 0) |
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perror("Failed to shutdown DV1394");
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/* Unmap ring buffer */
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if (munmap(dv->ring, DV1394_NTSC_FRAME_SIZE * DV1394_RING_FRAMES) < 0) |
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perror("Failed to munmap DV1394 ring buffer");
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close(dv->fd); |
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av_free(dv->dv_demux); |
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return 0; |
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} |
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static AVInputFormat dv1394_format = {
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.name = "dv1394",
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.long_name = "dv1394 A/V grab",
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.priv_data_size = sizeof(struct dv1394_data), |
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.read_header = dv1394_read_header, |
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.read_packet = dv1394_read_packet, |
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.read_close = dv1394_close, |
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.flags = AVFMT_NOFILE |
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}; |
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int dv1394_init(void) |
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{ |
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av_register_input_format(&dv1394_format); |
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return 0; |
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} |