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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 FFmpeg.
6  *
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.
11  *
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.
16  *
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
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 
30 #include "libavutil/log.h"
31 #include "libavutil/opt.h"
32 #include "avdevice.h"
33 #include "libavformat/dv.h"
34 #include "dv1394.h"
35 
36 struct dv1394_data {
37  AVClass *class;
38  int fd;
39  int channel;
40  int format;
41 
42  uint8_t *ring; /* Ring buffer */
43  int index; /* Current frame index */
44  int avail; /* Number of frames available for reading */
45  int done; /* Number of completed frames */
46 
47  DVDemuxContext* dv_demux; /* Generic DV muxing/demuxing context */
48 };
49 
50 /*
51  * The trick here is to kludge around well known problem with kernel Ooopsing
52  * when you try to capture PAL on a device node configure for NTSC. That's
53  * why we have to configure the device node for PAL, and then read only NTSC
54  * amount of data.
55  */
56 static int dv1394_reset(struct dv1394_data *dv)
57 {
58  struct dv1394_init init;
59 
60  init.channel = dv->channel;
63  init.format = DV1394_PAL;
64 
65  if (ioctl(dv->fd, DV1394_INIT, &init) < 0)
66  return -1;
67 
68  dv->avail = dv->done = 0;
69  return 0;
70 }
71 
72 static int dv1394_start(struct dv1394_data *dv)
73 {
74  /* Tell DV1394 driver to enable receiver */
75  if (ioctl(dv->fd, DV1394_START_RECEIVE, 0) < 0) {
76  av_log(NULL, AV_LOG_ERROR, "Failed to start receiver: %s\n", strerror(errno));
77  return -1;
78  }
79  return 0;
80 }
81 
82 static int dv1394_read_header(AVFormatContext * context)
83 {
84  struct dv1394_data *dv = context->priv_data;
85 
86  dv->dv_demux = avpriv_dv_init_demux(context);
87  if (!dv->dv_demux)
88  goto failed;
89 
90  /* Open and initialize DV1394 device */
91  dv->fd = open(context->filename, O_RDONLY);
92  if (dv->fd < 0) {
93  av_log(context, AV_LOG_ERROR, "Failed to open DV interface: %s\n", strerror(errno));
94  goto failed;
95  }
96 
97  if (dv1394_reset(dv) < 0) {
98  av_log(context, AV_LOG_ERROR, "Failed to initialize DV interface: %s\n", strerror(errno));
99  goto failed;
100  }
101 
102  dv->ring = mmap(NULL, DV1394_PAL_FRAME_SIZE * DV1394_RING_FRAMES,
103  PROT_READ, MAP_PRIVATE, dv->fd, 0);
104  if (dv->ring == MAP_FAILED) {
105  av_log(context, AV_LOG_ERROR, "Failed to mmap DV ring buffer: %s\n", strerror(errno));
106  goto failed;
107  }
108 
109  if (dv1394_start(dv) < 0)
110  goto failed;
111 
112  return 0;
113 
114 failed:
115  close(dv->fd);
116  return AVERROR(EIO);
117 }
118 
120 {
121  struct dv1394_data *dv = context->priv_data;
122  int size;
123 
124  size = avpriv_dv_get_packet(dv->dv_demux, pkt);
125  if (size > 0)
126  return size;
127 
128  if (!dv->avail) {
129  struct dv1394_status s;
130  struct pollfd p;
131 
132  if (dv->done) {
133  /* Request more frames */
134  if (ioctl(dv->fd, DV1394_RECEIVE_FRAMES, dv->done) < 0) {
135  /* This usually means that ring buffer overflowed.
136  * We have to reset :(.
137  */
138 
139  av_log(context, AV_LOG_ERROR, "DV1394: Ring buffer overflow. Reseting ..\n");
140 
141  dv1394_reset(dv);
142  dv1394_start(dv);
143  }
144  dv->done = 0;
145  }
146 
147  /* Wait until more frames are available */
148 restart_poll:
149  p.fd = dv->fd;
150  p.events = POLLIN | POLLERR | POLLHUP;
151  if (poll(&p, 1, -1) < 0) {
152  if (errno == EAGAIN || errno == EINTR)
153  goto restart_poll;
154  av_log(context, AV_LOG_ERROR, "Poll failed: %s\n", strerror(errno));
155  return AVERROR(EIO);
156  }
157 
158  if (ioctl(dv->fd, DV1394_GET_STATUS, &s) < 0) {
159  av_log(context, AV_LOG_ERROR, "Failed to get status: %s\n", strerror(errno));
160  return AVERROR(EIO);
161  }
162  av_dlog(context, "DV1394: status\n"
163  "\tactive_frame\t%d\n"
164  "\tfirst_clear_frame\t%d\n"
165  "\tn_clear_frames\t%d\n"
166  "\tdropped_frames\t%d\n",
169 
170  dv->avail = s.n_clear_frames;
171  dv->index = s.first_clear_frame;
172  dv->done = 0;
173 
174  if (s.dropped_frames) {
175  av_log(context, AV_LOG_ERROR, "DV1394: Frame drop detected (%d). Reseting ..\n",
176  s.dropped_frames);
177 
178  dv1394_reset(dv);
179  dv1394_start(dv);
180  }
181  }
182 
183  av_dlog(context, "index %d, avail %d, done %d\n", dv->index, dv->avail,
184  dv->done);
185 
186  size = avpriv_dv_produce_packet(dv->dv_demux, pkt,
187  dv->ring + (dv->index * DV1394_PAL_FRAME_SIZE),
189  dv->index = (dv->index + 1) % DV1394_RING_FRAMES;
190  dv->done++; dv->avail--;
191 
192  return size;
193 }
194 
195 static int dv1394_close(AVFormatContext * context)
196 {
197  struct dv1394_data *dv = context->priv_data;
198 
199  /* Shutdown DV1394 receiver */
200  if (ioctl(dv->fd, DV1394_SHUTDOWN, 0) < 0)
201  av_log(context, AV_LOG_ERROR, "Failed to shutdown DV1394: %s\n", strerror(errno));
202 
203  /* Unmap ring buffer */
204  if (munmap(dv->ring, DV1394_NTSC_FRAME_SIZE * DV1394_RING_FRAMES) < 0)
205  av_log(context, AV_LOG_ERROR, "Failed to munmap DV1394 ring buffer: %s\n", strerror(errno));
206 
207  close(dv->fd);
208  av_free(dv->dv_demux);
209 
210  return 0;
211 }
212 
213 static const AVOption options[] = {
214  { "standard", "", offsetof(struct dv1394_data, format), AV_OPT_TYPE_INT, {.i64 = DV1394_NTSC}, DV1394_NTSC, DV1394_PAL, AV_OPT_FLAG_DECODING_PARAM, "standard" },
215  { "PAL", "", 0, AV_OPT_TYPE_CONST, {.i64 = DV1394_PAL}, 0, 0, AV_OPT_FLAG_DECODING_PARAM, "standard" },
216  { "NTSC", "", 0, AV_OPT_TYPE_CONST, {.i64 = DV1394_NTSC}, 0, 0, AV_OPT_FLAG_DECODING_PARAM, "standard" },
217  { "channel", "", offsetof(struct dv1394_data, channel), AV_OPT_TYPE_INT, {.i64 = DV1394_DEFAULT_CHANNEL}, 0, INT_MAX, AV_OPT_FLAG_DECODING_PARAM },
218  { NULL },
219 };
220 
221 static const AVClass dv1394_class = {
222  .class_name = "DV1394 indev",
223  .item_name = av_default_item_name,
224  .option = options,
225  .version = LIBAVUTIL_VERSION_INT,
226 };
227 
229  .name = "dv1394",
230  .long_name = NULL_IF_CONFIG_SMALL("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,
236  .priv_class = &dv1394_class,
237 };