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 DVDemuxContext* dv_demux; /* Generic DV muxing/demuxing context */
50 * The trick here is to kludge around well known problem with kernel Ooopsing
51 * when you try to capture PAL on a device node configure for NTSC. That's
52 * why we have to configure the device node for PAL, and then read only NTSC
55 static int dv1394_reset(struct dv1394_data *dv)
57 struct dv1394_init init;
59 init.channel = dv->channel;
60 init.api_version = DV1394_API_VERSION;
61 init.n_frames = DV1394_RING_FRAMES;
62 init.format = DV1394_PAL;
64 if (ioctl(dv->fd, DV1394_INIT, &init) < 0)
67 dv->avail = dv->done = 0;
71 static int dv1394_start(struct dv1394_data *dv)
73 /* Tell DV1394 driver to enable receiver */
74 if (ioctl(dv->fd, DV1394_START_RECEIVE, 0) < 0) {
75 perror("Failed to start receiver");
81 static int dv1394_read_header(AVFormatContext * context, AVFormatParameters * ap)
83 struct dv1394_data *dv = context->priv_data;
84 const char *video_device;
86 dv->dv_demux = dv_init_demux(context);
90 if (ap->standard && !strcasecmp(ap->standard, "pal"))
91 dv->format = DV1394_PAL;
93 dv->format = DV1394_NTSC;
96 dv->channel = ap->channel;
98 dv->channel = DV1394_DEFAULT_CHANNEL;
100 /* Open and initialize DV1394 device */
101 video_device = ap->device;
103 video_device = "/dev/dv1394/0";
104 dv->fd = open(video_device, O_RDONLY);
106 perror("Failed to open DV interface");
110 if (dv1394_reset(dv) < 0) {
111 perror("Failed to initialize DV interface");
115 dv->ring = mmap(NULL, DV1394_PAL_FRAME_SIZE * DV1394_RING_FRAMES,
116 PROT_READ, MAP_PRIVATE, dv->fd, 0);
117 if (dv->ring == MAP_FAILED) {
118 perror("Failed to mmap DV ring buffer");
122 if (dv1394_start(dv) < 0)
132 static int dv1394_read_packet(AVFormatContext *context, AVPacket *pkt)
134 struct dv1394_data *dv = context->priv_data;
137 size = dv_get_packet(dv->dv_demux, pkt);
142 struct dv1394_status s;
146 /* Request more frames */
147 if (ioctl(dv->fd, DV1394_RECEIVE_FRAMES, dv->done) < 0) {
148 /* This usually means that ring buffer overflowed.
149 * We have to reset :(.
152 av_log(context, AV_LOG_ERROR, "DV1394: Ring buffer overflow. Reseting ..\n");
160 /* Wait until more frames are available */
163 p.events = POLLIN | POLLERR | POLLHUP;
164 if (poll(&p, 1, -1) < 0) {
165 if (errno == EAGAIN || errno == EINTR)
167 perror("Poll failed");
171 if (ioctl(dv->fd, DV1394_GET_STATUS, &s) < 0) {
172 perror("Failed to get status");
176 fprintf(stderr, "DV1394: status\n"
177 "\tactive_frame\t%d\n"
178 "\tfirst_clear_frame\t%d\n"
179 "\tn_clear_frames\t%d\n"
180 "\tdropped_frames\t%d\n",
181 s.active_frame, s.first_clear_frame,
182 s.n_clear_frames, s.dropped_frames);
185 dv->avail = s.n_clear_frames;
186 dv->index = s.first_clear_frame;
189 if (s.dropped_frames) {
190 av_log(context, AV_LOG_ERROR, "DV1394: Frame drop detected (%d). Reseting ..\n",
199 fprintf(stderr, "index %d, avail %d, done %d\n", dv->index, dv->avail,
203 size = dv_produce_packet(dv->dv_demux, pkt,
204 dv->ring + (dv->index * DV1394_PAL_FRAME_SIZE),
205 DV1394_PAL_FRAME_SIZE);
206 dv->index = (dv->index + 1) % DV1394_RING_FRAMES;
207 dv->done++; dv->avail--;
212 static int dv1394_close(AVFormatContext * context)
214 struct dv1394_data *dv = context->priv_data;
216 /* Shutdown DV1394 receiver */
217 if (ioctl(dv->fd, DV1394_SHUTDOWN, 0) < 0)
218 perror("Failed to shutdown DV1394");
220 /* Unmap ring buffer */
221 if (munmap(dv->ring, DV1394_NTSC_FRAME_SIZE * DV1394_RING_FRAMES) < 0)
222 perror("Failed to munmap DV1394 ring buffer");
225 av_free(dv->dv_demux);
230 static AVInputFormat dv1394_format = {
232 .long_name = "dv1394 A/V grab",
233 .priv_data_size = sizeof(struct dv1394_data),
234 .read_header = dv1394_read_header,
235 .read_packet = dv1394_read_packet,
236 .read_close = dv1394_close,
237 .flags = AVFMT_NOFILE
240 int dv1394_init(void)
242 av_register_input_format(&dv1394_format);