1 /*
2 * Copyright (c) 2001 Fabrice Bellard
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a copy
5 * of this software and associated documentation files (the "Software"), to deal
6 * in the Software without restriction, including without limitation the rights
7 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
8 * copies of the Software, and to permit persons to whom the Software is
9 * furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice shall be included in
12 * all copies or substantial portions of the Software.
13 *
14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
17 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
19 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
20 * THE SOFTWARE.
21 */
22
23 /**
24 * @file
25 * video encoding with libavcodec API example
26 *
27 * @example encode_video.c
28 */
29
30 #include <stdio.h>
31 #include <stdlib.h>
32 #include <string.h>
33
34 #include <libavcodec/avcodec.h>
35
36 #include <libavutil/opt.h>
37 #include <libavutil/imgutils.h>
38
encode(AVCodecContext * enc_ctx,AVFrame * frame,AVPacket * pkt,FILE * outfile)39 static void encode(AVCodecContext *enc_ctx, AVFrame *frame, AVPacket *pkt,
40 FILE *outfile)
41 {
42 int ret;
43
44 /* send the frame to the encoder */
45 if (frame)
46 printf("Send frame %3"PRId64"\n", frame->pts);
47
48 ret = avcodec_send_frame(enc_ctx, frame);
49 if (ret < 0) {
50 fprintf(stderr, "Error sending a frame for encoding\n");
51 exit(1);
52 }
53
54 while (ret >= 0) {
55 ret = avcodec_receive_packet(enc_ctx, pkt);
56 if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
57 return;
58 else if (ret < 0) {
59 fprintf(stderr, "Error during encoding\n");
60 exit(1);
61 }
62
63 printf("Write packet %3"PRId64" (size=%5d)\n", pkt->pts, pkt->size);
64 fwrite(pkt->data, 1, pkt->size, outfile);
65 av_packet_unref(pkt);
66 }
67 }
68
main(int argc,char ** argv)69 int main(int argc, char **argv)
70 {
71 const char *filename, *codec_name;
72 const AVCodec *codec;
73 AVCodecContext *c= NULL;
74 int i, ret, x, y;
75 FILE *f;
76 AVFrame *frame;
77 AVPacket *pkt;
78 uint8_t endcode[] = { 0, 0, 1, 0xb7 };
79
80 if (argc <= 2) {
81 fprintf(stderr, "Usage: %s <output file> <codec name>\n", argv[0]);
82 exit(0);
83 }
84 filename = argv[1];
85 codec_name = argv[2];
86
87 /* find the mpeg1video encoder */
88 codec = avcodec_find_encoder_by_name(codec_name);
89 if (!codec) {
90 fprintf(stderr, "Codec '%s' not found\n", codec_name);
91 exit(1);
92 }
93
94 c = avcodec_alloc_context3(codec);
95 if (!c) {
96 fprintf(stderr, "Could not allocate video codec context\n");
97 exit(1);
98 }
99
100 pkt = av_packet_alloc();
101 if (!pkt)
102 exit(1);
103
104 /* put sample parameters */
105 c->bit_rate = 400000;
106 /* resolution must be a multiple of two */
107 c->width = 352;
108 c->height = 288;
109 /* frames per second */
110 c->time_base = (AVRational){1, 25};
111 c->framerate = (AVRational){25, 1};
112
113 /* emit one intra frame every ten frames
114 * check frame pict_type before passing frame
115 * to encoder, if frame->pict_type is AV_PICTURE_TYPE_I
116 * then gop_size is ignored and the output of encoder
117 * will always be I frame irrespective to gop_size
118 */
119 c->gop_size = 10;
120 c->max_b_frames = 1;
121 c->pix_fmt = AV_PIX_FMT_YUV420P;
122
123 if (codec->id == AV_CODEC_ID_H264)
124 av_opt_set(c->priv_data, "preset", "slow", 0);
125
126 /* open it */
127 ret = avcodec_open2(c, codec, NULL);
128 if (ret < 0) {
129 fprintf(stderr, "Could not open codec: %s\n", av_err2str(ret));
130 exit(1);
131 }
132
133 f = fopen(filename, "wb");
134 if (!f) {
135 fprintf(stderr, "Could not open %s\n", filename);
136 exit(1);
137 }
138
139 frame = av_frame_alloc();
140 if (!frame) {
141 fprintf(stderr, "Could not allocate video frame\n");
142 exit(1);
143 }
144 frame->format = c->pix_fmt;
145 frame->width = c->width;
146 frame->height = c->height;
147
148 ret = av_frame_get_buffer(frame, 32);
149 if (ret < 0) {
150 fprintf(stderr, "Could not allocate the video frame data\n");
151 exit(1);
152 }
153
154 /* encode 1 second of video */
155 for (i = 0; i < 25; i++) {
156 fflush(stdout);
157
158 /* make sure the frame data is writable */
159 ret = av_frame_make_writable(frame);
160 if (ret < 0)
161 exit(1);
162
163 /* prepare a dummy image */
164 /* Y */
165 for (y = 0; y < c->height; y++) {
166 for (x = 0; x < c->width; x++) {
167 frame->data[0][y * frame->linesize[0] + x] = x + y + i * 3;
168 }
169 }
170
171 /* Cb and Cr */
172 for (y = 0; y < c->height/2; y++) {
173 for (x = 0; x < c->width/2; x++) {
174 frame->data[1][y * frame->linesize[1] + x] = 128 + y + i * 2;
175 frame->data[2][y * frame->linesize[2] + x] = 64 + x + i * 5;
176 }
177 }
178
179 frame->pts = i;
180
181 /* encode the image */
182 encode(c, frame, pkt, f);
183 }
184
185 /* flush the encoder */
186 encode(c, NULL, pkt, f);
187
188 /* add sequence end code to have a real MPEG file */
189 if (codec->id == AV_CODEC_ID_MPEG1VIDEO || codec->id == AV_CODEC_ID_MPEG2VIDEO)
190 fwrite(endcode, 1, sizeof(endcode), f);
191 fclose(f);
192
193 avcodec_free_context(&c);
194 av_frame_free(&frame);
195 av_packet_free(&pkt);
196
197 return 0;
198 }
199