dv1394.c
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1 /*
2  * Linux DV1394 interface
3  * Copyright (c) 2003 Max Krasnyansky <maxk@qualcomm.com>
4  *
5  * This file is part of Libav.
6  *
7  * Libav 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.
11  *
12  * Libav 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.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with Libav; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 #include "config.h"
23 #include <unistd.h>
24 #include <fcntl.h>
25 #include <errno.h>
26 #include <poll.h>
27 #include <sys/ioctl.h>
28 #include <sys/mman.h>
29 #include <sys/time.h>
30 #include <time.h>
31 
32 #include "libavutil/log.h"
33 #include "libavutil/opt.h"
34 #include "libavformat/avformat.h"
35 #include "libavformat/dv.h"
36 #include "dv1394.h"
37 
38 struct dv1394_data {
39  AVClass *class;
40  int fd;
41  int channel;
42  int format;
43 
44  uint8_t *ring; /* Ring buffer */
45  int index; /* Current frame index */
46  int avail; /* Number of frames available for reading */
47  int done; /* Number of completed frames */
48 
49  DVDemuxContext* dv_demux; /* Generic DV muxing/demuxing context */
50 };
51 
52 /*
53  * The trick here is to kludge around well known problem with kernel Ooopsing
54  * when you try to capture PAL on a device node configure for NTSC. That's
55  * why we have to configure the device node for PAL, and then read only NTSC
56  * amount of data.
57  */
58 static int dv1394_reset(struct dv1394_data *dv)
59 {
60  struct dv1394_init init;
61 
62  init.channel = dv->channel;
65  init.format = DV1394_PAL;
66 
67  if (ioctl(dv->fd, DV1394_INIT, &init) < 0)
68  return -1;
69 
70  dv->avail = dv->done = 0;
71  return 0;
72 }
73 
74 static int dv1394_start(struct dv1394_data *dv)
75 {
76  /* Tell DV1394 driver to enable receiver */
77  if (ioctl(dv->fd, DV1394_START_RECEIVE, 0) < 0) {
78  av_log(NULL, AV_LOG_ERROR, "Failed to start receiver: %s\n", strerror(errno));
79  return -1;
80  }
81  return 0;
82 }
83 
85 {
86  struct dv1394_data *dv = context->priv_data;
87 
88  dv->dv_demux = avpriv_dv_init_demux(context);
89  if (!dv->dv_demux)
90  goto failed;
91 
92  /* Open and initialize DV1394 device */
93  dv->fd = open(context->filename, O_RDONLY);
94  if (dv->fd < 0) {
95  av_log(context, AV_LOG_ERROR, "Failed to open DV interface: %s\n", strerror(errno));
96  goto failed;
97  }
98 
99  if (dv1394_reset(dv) < 0) {
100  av_log(context, AV_LOG_ERROR, "Failed to initialize DV interface: %s\n", strerror(errno));
101  goto failed;
102  }
103 
105  PROT_READ, MAP_PRIVATE, dv->fd, 0);
106  if (dv->ring == MAP_FAILED) {
107  av_log(context, AV_LOG_ERROR, "Failed to mmap DV ring buffer: %s\n", strerror(errno));
108  goto failed;
109  }
110 
111  if (dv1394_start(dv) < 0)
112  goto failed;
113 
114  return 0;
115 
116 failed:
117  close(dv->fd);
118  return AVERROR(EIO);
119 }
120 
121 static int dv1394_read_packet(AVFormatContext *context, AVPacket *pkt)
122 {
123  struct dv1394_data *dv = context->priv_data;
124  int size;
125 
126  size = avpriv_dv_get_packet(dv->dv_demux, pkt);
127  if (size > 0)
128  return size;
129 
130  if (!dv->avail) {
131  struct dv1394_status s;
132  struct pollfd p;
133 
134  if (dv->done) {
135  /* Request more frames */
136  if (ioctl(dv->fd, DV1394_RECEIVE_FRAMES, dv->done) < 0) {
137  /* This usually means that ring buffer overflowed.
138  * We have to reset :(.
139  */
140 
141  av_log(context, AV_LOG_ERROR, "DV1394: Ring buffer overflow. Reseting ..\n");
142 
143  dv1394_reset(dv);
144  dv1394_start(dv);
145  }
146  dv->done = 0;
147  }
148 
149  /* Wait until more frames are available */
150 restart_poll:
151  p.fd = dv->fd;
152  p.events = POLLIN | POLLERR | POLLHUP;
153  if (poll(&p, 1, -1) < 0) {
154  if (errno == EAGAIN || errno == EINTR)
155  goto restart_poll;
156  av_log(context, AV_LOG_ERROR, "Poll failed: %s\n", strerror(errno));
157  return AVERROR(EIO);
158  }
159 
160  if (ioctl(dv->fd, DV1394_GET_STATUS, &s) < 0) {
161  av_log(context, AV_LOG_ERROR, "Failed to get status: %s\n", strerror(errno));
162  return AVERROR(EIO);
163  }
164  av_dlog(context, "DV1394: status\n"
165  "\tactive_frame\t%d\n"
166  "\tfirst_clear_frame\t%d\n"
167  "\tn_clear_frames\t%d\n"
168  "\tdropped_frames\t%d\n",
171 
172  dv->avail = s.n_clear_frames;
173  dv->index = s.first_clear_frame;
174  dv->done = 0;
175 
176  if (s.dropped_frames) {
177  av_log(context, AV_LOG_ERROR, "DV1394: Frame drop detected (%d). Reseting ..\n",
178  s.dropped_frames);
179 
180  dv1394_reset(dv);
181  dv1394_start(dv);
182  }
183  }
184 
185  av_dlog(context, "index %d, avail %d, done %d\n", dv->index, dv->avail,
186  dv->done);
187 
188  size = avpriv_dv_produce_packet(dv->dv_demux, pkt,
189  dv->ring + (dv->index * DV1394_PAL_FRAME_SIZE),
191  dv->index = (dv->index + 1) % DV1394_RING_FRAMES;
192  dv->done++; dv->avail--;
193 
194  return size;
195 }
196 
197 static int dv1394_close(AVFormatContext * context)
198 {
199  struct dv1394_data *dv = context->priv_data;
200 
201  /* Shutdown DV1394 receiver */
202  if (ioctl(dv->fd, DV1394_SHUTDOWN, 0) < 0)
203  av_log(context, AV_LOG_ERROR, "Failed to shutdown DV1394: %s\n", strerror(errno));
204 
205  /* Unmap ring buffer */
206  if (munmap(dv->ring, DV1394_NTSC_FRAME_SIZE * DV1394_RING_FRAMES) < 0)
207  av_log(context, AV_LOG_ERROR, "Failed to munmap DV1394 ring buffer: %s\n", strerror(errno));
208 
209  close(dv->fd);
210  av_free(dv->dv_demux);
211 
212  return 0;
213 }
214 
215 static const AVOption options[] = {
216  { "standard", "", offsetof(struct dv1394_data, format), AV_OPT_TYPE_INT, {.dbl = DV1394_NTSC}, DV1394_PAL, DV1394_NTSC, AV_OPT_FLAG_DECODING_PARAM, "standard" },
217  { "PAL", "", 0, AV_OPT_TYPE_CONST, {.dbl = DV1394_PAL}, 0, 0, AV_OPT_FLAG_DECODING_PARAM, "standard" },
218  { "NTSC", "", 0, AV_OPT_TYPE_CONST, {.dbl = DV1394_NTSC}, 0, 0, AV_OPT_FLAG_DECODING_PARAM, "standard" },
219  { "channel", "", offsetof(struct dv1394_data, channel), AV_OPT_TYPE_INT, {.dbl = DV1394_DEFAULT_CHANNEL}, 0, INT_MAX, AV_OPT_FLAG_DECODING_PARAM },
220  { NULL },
221 };
222 
223 static const AVClass dv1394_class = {
224  .class_name = "DV1394 indev",
225  .item_name = av_default_item_name,
226  .option = options,
227  .version = LIBAVUTIL_VERSION_INT,
228 };
229 
231  .name = "dv1394",
232  .long_name = NULL_IF_CONFIG_SMALL("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,
238  .priv_class = &dv1394_class,
239 };