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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/internal.h"
31 #include "libavutil/log.h"
32 #include "libavutil/opt.h"
33 #include "avdevice.h"
34 #include "libavformat/dv.h"
35 #include "dv1394.h"
36 
37 struct dv1394_data {
38  AVClass *class;
39  int fd;
40  int channel;
41  int format;
42 
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 */
47 
48  DVDemuxContext* dv_demux; /* Generic DV muxing/demuxing context */
49 };
50 
51 /*
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
55  * amount of data.
56  */
57 static int dv1394_reset(struct dv1394_data *dv)
58 {
59  struct dv1394_init init;
60 
61  init.channel = dv->channel;
64  init.format = DV1394_PAL;
65 
66  if (ioctl(dv->fd, DV1394_INIT, &init) < 0)
67  return -1;
68 
69  dv->avail = dv->done = 0;
70  return 0;
71 }
72 
73 static int dv1394_start(struct dv1394_data *dv)
74 {
75  /* Tell DV1394 driver to enable receiver */
76  if (ioctl(dv->fd, DV1394_START_RECEIVE, 0) < 0) {
77  av_log(NULL, AV_LOG_ERROR, "Failed to start receiver: %s\n", strerror(errno));
78  return -1;
79  }
80  return 0;
81 }
82 
83 static int dv1394_read_header(AVFormatContext * context)
84 {
85  struct dv1394_data *dv = context->priv_data;
86 
87  dv->dv_demux = avpriv_dv_init_demux(context);
88  if (!dv->dv_demux)
89  goto failed;
90 
91  /* Open and initialize DV1394 device */
92  dv->fd = avpriv_open(context->filename, O_RDONLY);
93  if (dv->fd < 0) {
94  av_log(context, AV_LOG_ERROR, "Failed to open DV interface: %s\n", strerror(errno));
95  goto failed;
96  }
97 
98  if (dv1394_reset(dv) < 0) {
99  av_log(context, AV_LOG_ERROR, "Failed to initialize DV interface: %s\n", strerror(errno));
100  goto failed;
101  }
102 
103  dv->ring = mmap(NULL, DV1394_PAL_FRAME_SIZE * DV1394_RING_FRAMES,
104  PROT_READ, MAP_PRIVATE, dv->fd, 0);
105  if (dv->ring == MAP_FAILED) {
106  av_log(context, AV_LOG_ERROR, "Failed to mmap DV ring buffer: %s\n", strerror(errno));
107  goto failed;
108  }
109 
110  if (dv1394_start(dv) < 0)
111  goto failed;
112 
113  return 0;
114 
115 failed:
116  close(dv->fd);
117  return AVERROR(EIO);
118 }
119 
121 {
122  struct dv1394_data *dv = context->priv_data;
123  int size;
124 
125  size = avpriv_dv_get_packet(dv->dv_demux, pkt);
126  if (size > 0)
127  return size;
128 
129  if (!dv->avail) {
130  struct dv1394_status s;
131  struct pollfd p;
132 
133  if (dv->done) {
134  /* Request more frames */
135  if (ioctl(dv->fd, DV1394_RECEIVE_FRAMES, dv->done) < 0) {
136  /* This usually means that ring buffer overflowed.
137  * We have to reset :(.
138  */
139 
140  av_log(context, AV_LOG_ERROR, "DV1394: Ring buffer overflow. Reseting ..\n");
141 
142  dv1394_reset(dv);
143  dv1394_start(dv);
144  }
145  dv->done = 0;
146  }
147 
148  /* Wait until more frames are available */
149 restart_poll:
150  p.fd = dv->fd;
151  p.events = POLLIN | POLLERR | POLLHUP;
152  if (poll(&p, 1, -1) < 0) {
153  if (errno == EAGAIN || errno == EINTR)
154  goto restart_poll;
155  av_log(context, AV_LOG_ERROR, "Poll failed: %s\n", strerror(errno));
156  return AVERROR(EIO);
157  }
158 
159  if (ioctl(dv->fd, DV1394_GET_STATUS, &s) < 0) {
160  av_log(context, AV_LOG_ERROR, "Failed to get status: %s\n", strerror(errno));
161  return AVERROR(EIO);
162  }
163  av_dlog(context, "DV1394: status\n"
164  "\tactive_frame\t%d\n"
165  "\tfirst_clear_frame\t%d\n"
166  "\tn_clear_frames\t%d\n"
167  "\tdropped_frames\t%d\n",
170 
171  dv->avail = s.n_clear_frames;
172  dv->index = s.first_clear_frame;
173  dv->done = 0;
174 
175  if (s.dropped_frames) {
176  av_log(context, AV_LOG_ERROR, "DV1394: Frame drop detected (%d). Reseting ..\n",
177  s.dropped_frames);
178 
179  dv1394_reset(dv);
180  dv1394_start(dv);
181  }
182  }
183 
184  av_dlog(context, "index %d, avail %d, done %d\n", dv->index, dv->avail,
185  dv->done);
186 
187  size = avpriv_dv_produce_packet(dv->dv_demux, pkt,
188  dv->ring + (dv->index * DV1394_PAL_FRAME_SIZE),
190  dv->index = (dv->index + 1) % DV1394_RING_FRAMES;
191  dv->done++; dv->avail--;
192 
193  return size;
194 }
195 
196 static int dv1394_close(AVFormatContext * context)
197 {
198  struct dv1394_data *dv = context->priv_data;
199 
200  /* Shutdown DV1394 receiver */
201  if (ioctl(dv->fd, DV1394_SHUTDOWN, 0) < 0)
202  av_log(context, AV_LOG_ERROR, "Failed to shutdown DV1394: %s\n", strerror(errno));
203 
204  /* Unmap ring buffer */
205  if (munmap(dv->ring, DV1394_NTSC_FRAME_SIZE * DV1394_RING_FRAMES) < 0)
206  av_log(context, AV_LOG_ERROR, "Failed to munmap DV1394 ring buffer: %s\n", strerror(errno));
207 
208  close(dv->fd);
209  av_freep(&dv->dv_demux);
210 
211  return 0;
212 }
213 
214 static const AVOption options[] = {
215  { "standard", "", offsetof(struct dv1394_data, format), AV_OPT_TYPE_INT, {.i64 = DV1394_NTSC}, DV1394_NTSC, DV1394_PAL, AV_OPT_FLAG_DECODING_PARAM, "standard" },
216  { "PAL", "", 0, AV_OPT_TYPE_CONST, {.i64 = DV1394_PAL}, 0, 0, AV_OPT_FLAG_DECODING_PARAM, "standard" },
217  { "NTSC", "", 0, AV_OPT_TYPE_CONST, {.i64 = DV1394_NTSC}, 0, 0, AV_OPT_FLAG_DECODING_PARAM, "standard" },
218  { "channel", "", offsetof(struct dv1394_data, channel), AV_OPT_TYPE_INT, {.i64 = DV1394_DEFAULT_CHANNEL}, 0, INT_MAX, AV_OPT_FLAG_DECODING_PARAM },
219  { NULL },
220 };
221 
222 static const AVClass dv1394_class = {
223  .class_name = "DV1394 indev",
224  .item_name = av_default_item_name,
225  .option = options,
226  .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 };