2 * Linux DV1394 interface
3 * Copyright (c) 2003 Max Krasnyansky <maxk@qualcomm.com>
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 #include <sys/ioctl.h>
41 void *ring; /* Ring buffer */
42 int index; /* Current frame index */
43 int avail; /* Number of frames available for reading */
44 int done; /* Number of completed frames */
46 int64_t pts; /* Current timestamp */
48 DVDemuxContext* dv_demux; /* Generic DV muxing/demuxing context */
52 * The trick here is to kludge around well known problem with kernel Ooopsing
53 * when you try to capture PAL on a device node configure for NTSC. That's
54 * why we have to configure the device node for PAL, and then read only NTSC
57 static int dv1394_reset(struct dv1394_data *dv)
59 struct dv1394_init init;
61 init.channel = dv->channel;
62 init.api_version = DV1394_API_VERSION;
63 init.n_frames = DV1394_RING_FRAMES;
64 init.format = DV1394_PAL;
66 if (ioctl(dv->fd, DV1394_INIT, &init) < 0)
69 dv->avail = dv->done = 0;
73 static int dv1394_start(struct dv1394_data *dv)
75 /* Tell DV1394 driver to enable receiver */
76 if (ioctl(dv->fd, DV1394_START_RECEIVE, 0) < 0) {
77 perror("Failed to start receiver");
83 static int dv1394_read_header(AVFormatContext * context, AVFormatParameters * ap)
85 struct dv1394_data *dv = context->priv_data;
86 const char *video_device;
88 dv->dv_demux = dv_init_demux(context);
92 if (ap->standard && !strcasecmp(ap->standard, "pal"))
93 dv->format = DV1394_PAL;
95 dv->format = DV1394_NTSC;
98 dv->channel = ap->channel;
100 dv->channel = DV1394_DEFAULT_CHANNEL;
102 /* Open and initialize DV1394 device */
103 video_device = ap->device;
105 video_device = "/dev/dv1394/0";
106 dv->fd = open(video_device, O_RDONLY);
108 perror("Failed to open DV interface");
112 if (dv1394_reset(dv) < 0) {
113 perror("Failed to initialize DV interface");
117 dv->ring = mmap(NULL, DV1394_PAL_FRAME_SIZE * DV1394_RING_FRAMES,
118 PROT_READ, MAP_PRIVATE, dv->fd, 0);
119 if (dv->ring == MAP_FAILED) {
120 perror("Failed to mmap DV ring buffer");
124 av_set_pts_info(context, 48, 1, 1000000);
126 if (dv1394_start(dv) < 0)
136 static int dv1394_read_packet(AVFormatContext *context, AVPacket *pkt)
138 struct dv1394_data *dv = context->priv_data;
141 size = dv_get_packet(dv->dv_demux, pkt);
146 struct dv1394_status s;
150 /* Request more frames */
151 if (ioctl(dv->fd, DV1394_RECEIVE_FRAMES, dv->done) < 0) {
152 /* This usually means that ring buffer overflowed.
153 * We have to reset :(.
156 fprintf(stderr, "DV1394: Ring buffer overflow. Reseting ..\n");
164 /* Wait until more frames are available */
167 p.events = POLLIN | POLLERR | POLLHUP;
168 if (poll(&p, 1, -1) < 0) {
169 if (errno == EAGAIN || errno == EINTR)
171 perror("Poll failed");
175 if (ioctl(dv->fd, DV1394_GET_STATUS, &s) < 0) {
176 perror("Failed to get status");
180 fprintf(stderr, "DV1394: status\n"
181 "\tactive_frame\t%d\n"
182 "\tfirst_clear_frame\t%d\n"
183 "\tn_clear_frames\t%d\n"
184 "\tdropped_frames\t%d\n",
185 s.active_frame, s.first_clear_frame,
186 s.n_clear_frames, s.dropped_frames);
189 dv->avail = s.n_clear_frames;
190 dv->index = s.first_clear_frame;
193 if (s.dropped_frames) {
194 fprintf(stderr, "DV1394: Frame drop detected (%d). Reseting ..\n",
203 fprintf(stderr, "index %d, avail %d, done %d\n", dv->index, dv->avail,
207 size = dv_produce_packet(dv->dv_demux, pkt,
208 dv->ring + (dv->index * DV1394_PAL_FRAME_SIZE),
209 DV1394_PAL_FRAME_SIZE);
210 dv->index = (dv->index + 1) % DV1394_RING_FRAMES;
211 dv->done++; dv->avail--;
212 dv->pts = av_gettime() & ((1LL << 48) - 1);
219 static int dv1394_close(AVFormatContext * context)
221 struct dv1394_data *dv = context->priv_data;
223 /* Shutdown DV1394 receiver */
224 if (ioctl(dv->fd, DV1394_SHUTDOWN, 0) < 0)
225 perror("Failed to shutdown DV1394");
227 /* Unmap ring buffer */
228 if (munmap(dv->ring, DV1394_NTSC_FRAME_SIZE * DV1394_RING_FRAMES) < 0)
229 perror("Failed to munmap DV1394 ring buffer");
232 av_free(dv->dv_demux);
237 static AVInputFormat dv1394_format = {
239 .long_name = "dv1394 A/V grab",
240 .priv_data_size = sizeof(struct dv1394_data),
241 .read_header = dv1394_read_header,
242 .read_packet = dv1394_read_packet,
243 .read_close = dv1394_close,
244 .flags = AVFMT_NOFILE
247 int dv1394_init(void)
249 av_register_input_format(&dv1394_format);