1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
|
/*
* V4L2 mem2mem decoders
*
* Copyright (C) 2017 Alexis Ballier <aballier@gentoo.org>
* Copyright (C) 2017 Jorge Ramirez <jorge.ramirez-ortiz@linaro.org>
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <linux/videodev2.h>
#include <sys/ioctl.h>
#include "libavutil/pixfmt.h"
#include "libavutil/pixdesc.h"
#include "libavutil/opt.h"
#include "libavcodec/avcodec.h"
#include "libavcodec/decode.h"
#include "v4l2_context.h"
#include "v4l2_m2m.h"
#include "v4l2_fmt.h"
static int v4l2_try_start(AVCodecContext *avctx)
{
V4L2m2mContext *s = ((V4L2m2mPriv*)avctx->priv_data)->context;
V4L2Context *const capture = &s->capture;
V4L2Context *const output = &s->output;
struct v4l2_selection selection;
int ret;
/* 1. start the output process */
if (!output->streamon) {
ret = ff_v4l2_context_set_status(output, VIDIOC_STREAMON);
if (ret < 0) {
av_log(avctx, AV_LOG_DEBUG, "VIDIOC_STREAMON on output context\n");
return ret;
}
}
if (capture->streamon)
return 0;
/* 2. get the capture format */
capture->format.type = capture->type;
ret = ioctl(s->fd, VIDIOC_G_FMT, &capture->format);
if (ret) {
av_log(avctx, AV_LOG_WARNING, "VIDIOC_G_FMT ioctl\n");
return ret;
}
/* 2.1 update the AVCodecContext */
avctx->pix_fmt = ff_v4l2_format_v4l2_to_avfmt(capture->format.fmt.pix_mp.pixelformat, AV_CODEC_ID_RAWVIDEO);
capture->av_pix_fmt = avctx->pix_fmt;
/* 3. set the crop parameters */
selection.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
selection.r.height = avctx->coded_height;
selection.r.width = avctx->coded_width;
ret = ioctl(s->fd, VIDIOC_S_SELECTION, &selection);
if (!ret) {
ret = ioctl(s->fd, VIDIOC_G_SELECTION, &selection);
if (ret) {
av_log(avctx, AV_LOG_WARNING, "VIDIOC_G_SELECTION ioctl\n");
} else {
av_log(avctx, AV_LOG_DEBUG, "crop output %dx%d\n", selection.r.width, selection.r.height);
/* update the size of the resulting frame */
capture->height = selection.r.height;
capture->width = selection.r.width;
}
}
/* 4. init the capture context now that we have the capture format */
if (!capture->buffers) {
ret = ff_v4l2_context_init(capture);
if (ret) {
av_log(avctx, AV_LOG_DEBUG, "can't request output buffers\n");
return ret;
}
}
/* 5. start the capture process */
ret = ff_v4l2_context_set_status(capture, VIDIOC_STREAMON);
if (ret) {
av_log(avctx, AV_LOG_DEBUG, "VIDIOC_STREAMON, on capture context\n");
return ret;
}
return 0;
}
static int v4l2_prepare_decoder(V4L2m2mContext *s)
{
struct v4l2_event_subscription sub;
V4L2Context *output = &s->output;
int ret;
/**
* requirements
*/
memset(&sub, 0, sizeof(sub));
sub.type = V4L2_EVENT_SOURCE_CHANGE;
ret = ioctl(s->fd, VIDIOC_SUBSCRIBE_EVENT, &sub);
if ( ret < 0) {
if (output->height == 0 || output->width == 0) {
av_log(s->avctx, AV_LOG_ERROR,
"the v4l2 driver does not support VIDIOC_SUBSCRIBE_EVENT\n"
"you must provide codec_height and codec_width on input\n");
return ret;
}
}
return 0;
}
static int v4l2_receive_frame(AVCodecContext *avctx, AVFrame *frame)
{
V4L2m2mContext *s = ((V4L2m2mPriv*)avctx->priv_data)->context;
V4L2Context *const capture = &s->capture;
V4L2Context *const output = &s->output;
AVPacket avpkt = {0};
int ret;
ret = ff_decode_get_packet(avctx, &avpkt);
if (ret < 0 && ret != AVERROR_EOF)
return ret;
if (s->draining)
goto dequeue;
ret = ff_v4l2_context_enqueue_packet(output, &avpkt);
if (ret < 0) {
if (ret != AVERROR(ENOMEM))
return ret;
/* no input buffers available, continue dequeing */
}
if (avpkt.size) {
ret = v4l2_try_start(avctx);
if (ret)
return 0;
}
dequeue:
return ff_v4l2_context_dequeue_frame(capture, frame);
}
static av_cold int v4l2_decode_init(AVCodecContext *avctx)
{
V4L2Context *capture, *output;
V4L2m2mContext *s;
int ret;
ret = ff_v4l2_m2m_create_context(avctx, &s);
if (ret < 0)
return ret;
capture = &s->capture;
output = &s->output;
/* if these dimensions are invalid (ie, 0 or too small) an event will be raised
* by the v4l2 driver; this event will trigger a full pipeline reconfig and
* the proper values will be retrieved from the kernel driver.
*/
output->height = capture->height = avctx->coded_height;
output->width = capture->width = avctx->coded_width;
output->av_codec_id = avctx->codec_id;
output->av_pix_fmt = AV_PIX_FMT_NONE;
capture->av_codec_id = AV_CODEC_ID_RAWVIDEO;
capture->av_pix_fmt = avctx->pix_fmt;
ret = ff_v4l2_m2m_codec_init(avctx);
if (ret) {
av_log(avctx, AV_LOG_ERROR, "can't configure decoder\n");
return ret;
}
return v4l2_prepare_decoder(s);
}
#define OFFSET(x) offsetof(V4L2m2mPriv, x)
#define FLAGS AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_DECODING_PARAM
static const AVOption options[] = {
V4L_M2M_DEFAULT_OPTS,
{ "num_capture_buffers", "Number of buffers in the capture context",
OFFSET(num_capture_buffers), AV_OPT_TYPE_INT, {.i64 = 20}, 20, INT_MAX, FLAGS },
{ NULL},
};
#define M2MDEC(NAME, LONGNAME, CODEC, bsf_name) \
static const AVClass v4l2_m2m_ ## NAME ## _dec_class = {\
.class_name = #NAME "_v4l2_m2m_decoder",\
.item_name = av_default_item_name,\
.option = options,\
.version = LIBAVUTIL_VERSION_INT,\
};\
\
AVCodec ff_ ## NAME ## _v4l2m2m_decoder = { \
.name = #NAME "_v4l2m2m" ,\
.long_name = NULL_IF_CONFIG_SMALL("V4L2 mem2mem " LONGNAME " decoder wrapper"),\
.type = AVMEDIA_TYPE_VIDEO,\
.id = CODEC ,\
.priv_data_size = sizeof(V4L2m2mPriv),\
.priv_class = &v4l2_m2m_ ## NAME ## _dec_class,\
.init = v4l2_decode_init,\
.receive_frame = v4l2_receive_frame,\
.close = ff_v4l2_m2m_codec_end,\
.bsfs = bsf_name, \
.capabilities = AV_CODEC_CAP_HARDWARE | AV_CODEC_CAP_DELAY | \
AV_CODEC_CAP_AVOID_PROBING, \
.wrapper_name = "v4l2m2m", \
};
M2MDEC(h264, "H.264", AV_CODEC_ID_H264, "h264_mp4toannexb");
M2MDEC(hevc, "HEVC", AV_CODEC_ID_HEVC, "hevc_mp4toannexb");
M2MDEC(mpeg1, "MPEG1", AV_CODEC_ID_MPEG1VIDEO, NULL);
M2MDEC(mpeg2, "MPEG2", AV_CODEC_ID_MPEG2VIDEO, NULL);
M2MDEC(mpeg4, "MPEG4", AV_CODEC_ID_MPEG4, NULL);
M2MDEC(h263, "H.263", AV_CODEC_ID_H263, NULL);
M2MDEC(vc1 , "VC1", AV_CODEC_ID_VC1, NULL);
M2MDEC(vp8, "VP8", AV_CODEC_ID_VP8, NULL);
M2MDEC(vp9, "VP9", AV_CODEC_ID_VP9, NULL);
|
