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#include <sys/time.h>
30#include <time.h>
31#include <strings.h>
32
33#include "libavformat/avformat.h"
34
35#undef DV1394_DEBUG
36
37#include "libavformat/dv.h"
38#include "dv1394.h"
39
40struct dv1394_data {
41    int fd;
42    int channel;
43    int format;
44
45    uint8_t *ring; /* Ring buffer */
46    int index;  /* Current frame index */
47    int avail;  /* Number of frames available for reading */
48    int done;   /* Number of completed frames */
49
50    DVDemuxContext* dv_demux; /* Generic DV muxing/demuxing context */
51};
52
53/*
54 * The trick here is to kludge around well known problem with kernel Ooopsing
55 * when you try to capture PAL on a device node configure for NTSC. That's
56 * why we have to configure the device node for PAL, and then read only NTSC
57 * amount of data.
58 */
59static int dv1394_reset(struct dv1394_data *dv)
60{
61    struct dv1394_init init;
62
63    init.channel     = dv->channel;
64    init.api_version = DV1394_API_VERSION;
65    init.n_frames    = DV1394_RING_FRAMES;
66    init.format      = DV1394_PAL;
67
68    if (ioctl(dv->fd, DV1394_INIT, &init) < 0)
69        return -1;
70
71    dv->avail  = dv->done = 0;
72    return 0;
73}
74
75static int dv1394_start(struct dv1394_data *dv)
76{
77    /* Tell DV1394 driver to enable receiver */
78    if (ioctl(dv->fd, DV1394_START_RECEIVE, 0) < 0) {
79        av_log(NULL, AV_LOG_ERROR, "Failed to start receiver: %s\n", strerror(errno));
80        return -1;
81    }
82    return 0;
83}
84
85static int dv1394_read_header(AVFormatContext * context, AVFormatParameters * ap)
86{
87    struct dv1394_data *dv = context->priv_data;
88
89    dv->dv_demux = dv_init_demux(context);
90    if (!dv->dv_demux)
91        goto failed;
92
93    if (ap->standard && !strcasecmp(ap->standard, "pal"))
94        dv->format = DV1394_PAL;
95    else
96        dv->format = DV1394_NTSC;
97
98    if (ap->channel)
99        dv->channel = ap->channel;
100    else
101        dv->channel = DV1394_DEFAULT_CHANNEL;
102
103    /* Open and initialize DV1394 device */
104    dv->fd = open(context->filename, O_RDONLY);
105    if (dv->fd < 0) {
106        av_log(context, AV_LOG_ERROR, "Failed to open DV interface: %s\n", strerror(errno));
107        goto failed;
108    }
109
110    if (dv1394_reset(dv) < 0) {
111        av_log(context, AV_LOG_ERROR, "Failed to initialize DV interface: %s\n", strerror(errno));
112        goto failed;
113    }
114
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        av_log(context, AV_LOG_ERROR, "Failed to mmap DV ring buffer: %s\n", strerror(errno));
119        goto failed;
120    }
121
122    if (dv1394_start(dv) < 0)
123        goto failed;
124
125    return 0;
126
127failed:
128    close(dv->fd);
129    return AVERROR(EIO);
130}
131
132static int dv1394_read_packet(AVFormatContext *context, AVPacket *pkt)
133{
134    struct dv1394_data *dv = context->priv_data;
135    int size;
136
137    size = dv_get_packet(dv->dv_demux, pkt);
138    if (size > 0)
139        return size;
140
141    if (!dv->avail) {
142        struct dv1394_status s;
143        struct pollfd p;
144
145        if (dv->done) {
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 :(.
150                 */
151
152                av_log(context, AV_LOG_ERROR, "DV1394: Ring buffer overflow. Reseting ..\n");
153
154                dv1394_reset(dv);
155                dv1394_start(dv);
156            }
157            dv->done = 0;
158        }
159
160        /* Wait until more frames are available */
161restart_poll:
162        p.fd = dv->fd;
163        p.events = POLLIN | POLLERR | POLLHUP;
164        if (poll(&p, 1, -1) < 0) {
165            if (errno == EAGAIN || errno == EINTR)
166                goto restart_poll;
167            av_log(context, AV_LOG_ERROR, "Poll failed: %s\n", strerror(errno));
168            return AVERROR(EIO);
169        }
170
171        if (ioctl(dv->fd, DV1394_GET_STATUS, &s) < 0) {
172            av_log(context, AV_LOG_ERROR, "Failed to get status: %s\n", strerror(errno));
173            return AVERROR(EIO);
174        }
175#ifdef DV1394_DEBUG
176        av_log(context, AV_LOG_DEBUG, "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);
183#endif
184
185        dv->avail = s.n_clear_frames;
186        dv->index = s.first_clear_frame;
187        dv->done  = 0;
188
189        if (s.dropped_frames) {
190            av_log(context, AV_LOG_ERROR, "DV1394: Frame drop detected (%d). Reseting ..\n",
191                    s.dropped_frames);
192
193            dv1394_reset(dv);
194            dv1394_start(dv);
195        }
196    }
197
198#ifdef DV1394_DEBUG
199    av_log(context, AV_LOG_DEBUG, "index %d, avail %d, done %d\n", dv->index, dv->avail,
200            dv->done);
201#endif
202
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--;
208
209    return size;
210}
211
212static int dv1394_close(AVFormatContext * context)
213{
214    struct dv1394_data *dv = context->priv_data;
215
216    /* Shutdown DV1394 receiver */
217    if (ioctl(dv->fd, DV1394_SHUTDOWN, 0) < 0)
218        av_log(context, AV_LOG_ERROR, "Failed to shutdown DV1394: %s\n", strerror(errno));
219
220    /* Unmap ring buffer */
221    if (munmap(dv->ring, DV1394_NTSC_FRAME_SIZE * DV1394_RING_FRAMES) < 0)
222        av_log(context, AV_LOG_ERROR, "Failed to munmap DV1394 ring buffer: %s\n", strerror(errno));
223
224    close(dv->fd);
225    av_free(dv->dv_demux);
226
227    return 0;
228}
229
230AVInputFormat dv1394_demuxer = {
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};
239