2 * Linux DV1394 interface
3 * Copyright (c) 2003 Max Krasnyansky <maxk@qualcomm.com>
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
25 #include <sys/ioctl.h>
43 uint8_t *ring; /* Ring buffer */
44 int index; /* Current frame index */
45 int avail; /* Number of frames available for reading */
46 int done; /* Number of completed frames */
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;
87 dv->dv_demux = dv_init_demux(context);
91 if (ap->standard && !strcasecmp(ap->standard, "pal"))
92 dv->format = DV1394_PAL;
94 dv->format = DV1394_NTSC;
97 dv->channel = ap->channel;
99 dv->channel = DV1394_DEFAULT_CHANNEL;
101 /* Open and initialize DV1394 device */
102 dv->fd = open(context->filename, O_RDONLY);
104 perror("Failed to open DV interface");
108 if (dv1394_reset(dv) < 0) {
109 perror("Failed to initialize DV interface");
113 dv->ring = mmap(NULL, DV1394_PAL_FRAME_SIZE * DV1394_RING_FRAMES,
114 PROT_READ, MAP_PRIVATE, dv->fd, 0);
115 if (dv->ring == MAP_FAILED) {
116 perror("Failed to mmap DV ring buffer");
120 if (dv1394_start(dv) < 0)
130 static int dv1394_read_packet(AVFormatContext *context, AVPacket *pkt)
132 struct dv1394_data *dv = context->priv_data;
135 size = dv_get_packet(dv->dv_demux, pkt);
140 struct dv1394_status s;
144 /* Request more frames */
145 if (ioctl(dv->fd, DV1394_RECEIVE_FRAMES, dv->done) < 0) {
146 /* This usually means that ring buffer overflowed.
147 * We have to reset :(.
150 av_log(context, AV_LOG_ERROR, "DV1394: Ring buffer overflow. Reseting ..\n");
158 /* Wait until more frames are available */
161 p.events = POLLIN | POLLERR | POLLHUP;
162 if (poll(&p, 1, -1) < 0) {
163 if (errno == EAGAIN || errno == EINTR)
165 perror("Poll failed");
169 if (ioctl(dv->fd, DV1394_GET_STATUS, &s) < 0) {
170 perror("Failed to get status");
174 av_log(context, AV_LOG_DEBUG, "DV1394: status\n"
175 "\tactive_frame\t%d\n"
176 "\tfirst_clear_frame\t%d\n"
177 "\tn_clear_frames\t%d\n"
178 "\tdropped_frames\t%d\n",
179 s.active_frame, s.first_clear_frame,
180 s.n_clear_frames, s.dropped_frames);
183 dv->avail = s.n_clear_frames;
184 dv->index = s.first_clear_frame;
187 if (s.dropped_frames) {
188 av_log(context, AV_LOG_ERROR, "DV1394: Frame drop detected (%d). Reseting ..\n",
197 av_log(context, AV_LOG_DEBUG, "index %d, avail %d, done %d\n", dv->index, dv->avail,
201 size = dv_produce_packet(dv->dv_demux, pkt,
202 dv->ring + (dv->index * DV1394_PAL_FRAME_SIZE),
203 DV1394_PAL_FRAME_SIZE);
204 dv->index = (dv->index + 1) % DV1394_RING_FRAMES;
205 dv->done++; dv->avail--;
210 static int dv1394_close(AVFormatContext * context)
212 struct dv1394_data *dv = context->priv_data;
214 /* Shutdown DV1394 receiver */
215 if (ioctl(dv->fd, DV1394_SHUTDOWN, 0) < 0)
216 perror("Failed to shutdown DV1394");
218 /* Unmap ring buffer */
219 if (munmap(dv->ring, DV1394_NTSC_FRAME_SIZE * DV1394_RING_FRAMES) < 0)
220 perror("Failed to munmap DV1394 ring buffer");
223 av_free(dv->dv_demux);
228 AVInputFormat dv1394_demuxer = {
230 .long_name = "dv1394 A/V grab",
231 .priv_data_size = sizeof(struct dv1394_data),
232 .read_header = dv1394_read_header,
233 .read_packet = dv1394_read_packet,
234 .read_close = dv1394_close,
235 .flags = AVFMT_NOFILE