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1 | /* |
2 | * Copyright (c) 2010 Nicolas George | |
3 | * Copyright (c) 2011 Stefano Sabatini | |
4 | * | |
5 | * Permission is hereby granted, free of charge, to any person obtaining a copy | |
6 | * of this software and associated documentation files (the "Software"), to deal | |
7 | * in the Software without restriction, including without limitation the rights | |
8 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell | |
9 | * copies of the Software, and to permit persons to whom the Software is | |
10 | * furnished to do so, subject to the following conditions: | |
11 | * | |
12 | * The above copyright notice and this permission notice shall be included in | |
13 | * all copies or substantial portions of the Software. | |
14 | * | |
15 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
16 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
17 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL | |
18 | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
19 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, | |
20 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN | |
21 | * THE SOFTWARE. | |
22 | */ | |
23 | ||
24 | /** | |
25 | * @file | |
26 | * API example for decoding and filtering | |
27 | * @example filtering_video.c | |
28 | */ | |
29 | ||
30 | #define _XOPEN_SOURCE 600 /* for usleep */ | |
31 | #include <unistd.h> | |
32 | ||
33 | #include <libavcodec/avcodec.h> | |
34 | #include <libavformat/avformat.h> | |
35 | #include <libavfilter/avfiltergraph.h> | |
36 | #include <libavfilter/avcodec.h> | |
37 | #include <libavfilter/buffersink.h> | |
38 | #include <libavfilter/buffersrc.h> | |
39 | #include <libavutil/opt.h> | |
40 | ||
41 | const char *filter_descr = "scale=78:24"; | |
42 | ||
43 | static AVFormatContext *fmt_ctx; | |
44 | static AVCodecContext *dec_ctx; | |
45 | AVFilterContext *buffersink_ctx; | |
46 | AVFilterContext *buffersrc_ctx; | |
47 | AVFilterGraph *filter_graph; | |
48 | static int video_stream_index = -1; | |
49 | static int64_t last_pts = AV_NOPTS_VALUE; | |
50 | ||
51 | static int open_input_file(const char *filename) | |
52 | { | |
53 | int ret; | |
54 | AVCodec *dec; | |
55 | ||
56 | if ((ret = avformat_open_input(&fmt_ctx, filename, NULL, NULL)) < 0) { | |
57 | av_log(NULL, AV_LOG_ERROR, "Cannot open input file\n"); | |
58 | return ret; | |
59 | } | |
60 | ||
61 | if ((ret = avformat_find_stream_info(fmt_ctx, NULL)) < 0) { | |
62 | av_log(NULL, AV_LOG_ERROR, "Cannot find stream information\n"); | |
63 | return ret; | |
64 | } | |
65 | ||
66 | /* select the video stream */ | |
67 | ret = av_find_best_stream(fmt_ctx, AVMEDIA_TYPE_VIDEO, -1, -1, &dec, 0); | |
68 | if (ret < 0) { | |
69 | av_log(NULL, AV_LOG_ERROR, "Cannot find a video stream in the input file\n"); | |
70 | return ret; | |
71 | } | |
72 | video_stream_index = ret; | |
73 | dec_ctx = fmt_ctx->streams[video_stream_index]->codec; | |
74 | av_opt_set_int(dec_ctx, "refcounted_frames", 1, 0); | |
75 | ||
76 | /* init the video decoder */ | |
77 | if ((ret = avcodec_open2(dec_ctx, dec, NULL)) < 0) { | |
78 | av_log(NULL, AV_LOG_ERROR, "Cannot open video decoder\n"); | |
79 | return ret; | |
80 | } | |
81 | ||
82 | return 0; | |
83 | } | |
84 | ||
85 | static int init_filters(const char *filters_descr) | |
86 | { | |
87 | char args[512]; | |
88 | int ret = 0; | |
89 | AVFilter *buffersrc = avfilter_get_by_name("buffer"); | |
90 | AVFilter *buffersink = avfilter_get_by_name("buffersink"); | |
91 | AVFilterInOut *outputs = avfilter_inout_alloc(); | |
92 | AVFilterInOut *inputs = avfilter_inout_alloc(); | |
93 | enum AVPixelFormat pix_fmts[] = { AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE }; | |
94 | ||
95 | filter_graph = avfilter_graph_alloc(); | |
96 | if (!outputs || !inputs || !filter_graph) { | |
97 | ret = AVERROR(ENOMEM); | |
98 | goto end; | |
99 | } | |
100 | ||
101 | /* buffer video source: the decoded frames from the decoder will be inserted here. */ | |
102 | snprintf(args, sizeof(args), | |
103 | "video_size=%dx%d:pix_fmt=%d:time_base=%d/%d:pixel_aspect=%d/%d", | |
104 | dec_ctx->width, dec_ctx->height, dec_ctx->pix_fmt, | |
105 | dec_ctx->time_base.num, dec_ctx->time_base.den, | |
106 | dec_ctx->sample_aspect_ratio.num, dec_ctx->sample_aspect_ratio.den); | |
107 | ||
108 | ret = avfilter_graph_create_filter(&buffersrc_ctx, buffersrc, "in", | |
109 | args, NULL, filter_graph); | |
110 | if (ret < 0) { | |
111 | av_log(NULL, AV_LOG_ERROR, "Cannot create buffer source\n"); | |
112 | goto end; | |
113 | } | |
114 | ||
115 | /* buffer video sink: to terminate the filter chain. */ | |
116 | ret = avfilter_graph_create_filter(&buffersink_ctx, buffersink, "out", | |
117 | NULL, NULL, filter_graph); | |
118 | if (ret < 0) { | |
119 | av_log(NULL, AV_LOG_ERROR, "Cannot create buffer sink\n"); | |
120 | goto end; | |
121 | } | |
122 | ||
123 | ret = av_opt_set_int_list(buffersink_ctx, "pix_fmts", pix_fmts, | |
124 | AV_PIX_FMT_NONE, AV_OPT_SEARCH_CHILDREN); | |
125 | if (ret < 0) { | |
126 | av_log(NULL, AV_LOG_ERROR, "Cannot set output pixel format\n"); | |
127 | goto end; | |
128 | } | |
129 | ||
130 | /* Endpoints for the filter graph. */ | |
131 | outputs->name = av_strdup("in"); | |
132 | outputs->filter_ctx = buffersrc_ctx; | |
133 | outputs->pad_idx = 0; | |
134 | outputs->next = NULL; | |
135 | ||
136 | inputs->name = av_strdup("out"); | |
137 | inputs->filter_ctx = buffersink_ctx; | |
138 | inputs->pad_idx = 0; | |
139 | inputs->next = NULL; | |
140 | ||
141 | if ((ret = avfilter_graph_parse_ptr(filter_graph, filters_descr, | |
142 | &inputs, &outputs, NULL)) < 0) | |
143 | goto end; | |
144 | ||
145 | if ((ret = avfilter_graph_config(filter_graph, NULL)) < 0) | |
146 | goto end; | |
147 | ||
148 | end: | |
149 | avfilter_inout_free(&inputs); | |
150 | avfilter_inout_free(&outputs); | |
151 | ||
152 | return ret; | |
153 | } | |
154 | ||
155 | static void display_frame(const AVFrame *frame, AVRational time_base) | |
156 | { | |
157 | int x, y; | |
158 | uint8_t *p0, *p; | |
159 | int64_t delay; | |
160 | ||
161 | if (frame->pts != AV_NOPTS_VALUE) { | |
162 | if (last_pts != AV_NOPTS_VALUE) { | |
163 | /* sleep roughly the right amount of time; | |
164 | * usleep is in microseconds, just like AV_TIME_BASE. */ | |
165 | delay = av_rescale_q(frame->pts - last_pts, | |
166 | time_base, AV_TIME_BASE_Q); | |
167 | if (delay > 0 && delay < 1000000) | |
168 | usleep(delay); | |
169 | } | |
170 | last_pts = frame->pts; | |
171 | } | |
172 | ||
173 | /* Trivial ASCII grayscale display. */ | |
174 | p0 = frame->data[0]; | |
175 | puts("\033c"); | |
176 | for (y = 0; y < frame->height; y++) { | |
177 | p = p0; | |
178 | for (x = 0; x < frame->width; x++) | |
179 | putchar(" .-+#"[*(p++) / 52]); | |
180 | putchar('\n'); | |
181 | p0 += frame->linesize[0]; | |
182 | } | |
183 | fflush(stdout); | |
184 | } | |
185 | ||
186 | int main(int argc, char **argv) | |
187 | { | |
188 | int ret; | |
189 | AVPacket packet; | |
190 | AVFrame *frame = av_frame_alloc(); | |
191 | AVFrame *filt_frame = av_frame_alloc(); | |
192 | int got_frame; | |
193 | ||
194 | if (!frame || !filt_frame) { | |
195 | perror("Could not allocate frame"); | |
196 | exit(1); | |
197 | } | |
198 | if (argc != 2) { | |
199 | fprintf(stderr, "Usage: %s file\n", argv[0]); | |
200 | exit(1); | |
201 | } | |
202 | ||
203 | av_register_all(); | |
204 | avfilter_register_all(); | |
205 | ||
206 | if ((ret = open_input_file(argv[1])) < 0) | |
207 | goto end; | |
208 | if ((ret = init_filters(filter_descr)) < 0) | |
209 | goto end; | |
210 | ||
211 | /* read all packets */ | |
212 | while (1) { | |
213 | if ((ret = av_read_frame(fmt_ctx, &packet)) < 0) | |
214 | break; | |
215 | ||
216 | if (packet.stream_index == video_stream_index) { | |
217 | got_frame = 0; | |
218 | ret = avcodec_decode_video2(dec_ctx, frame, &got_frame, &packet); | |
219 | if (ret < 0) { | |
220 | av_log(NULL, AV_LOG_ERROR, "Error decoding video\n"); | |
221 | break; | |
222 | } | |
223 | ||
224 | if (got_frame) { | |
225 | frame->pts = av_frame_get_best_effort_timestamp(frame); | |
226 | ||
227 | /* push the decoded frame into the filtergraph */ | |
228 | if (av_buffersrc_add_frame_flags(buffersrc_ctx, frame, AV_BUFFERSRC_FLAG_KEEP_REF) < 0) { | |
229 | av_log(NULL, AV_LOG_ERROR, "Error while feeding the filtergraph\n"); | |
230 | break; | |
231 | } | |
232 | ||
233 | /* pull filtered frames from the filtergraph */ | |
234 | while (1) { | |
235 | ret = av_buffersink_get_frame(buffersink_ctx, filt_frame); | |
236 | if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF) | |
237 | break; | |
238 | if (ret < 0) | |
239 | goto end; | |
240 | display_frame(filt_frame, buffersink_ctx->inputs[0]->time_base); | |
241 | av_frame_unref(filt_frame); | |
242 | } | |
243 | av_frame_unref(frame); | |
244 | } | |
245 | } | |
246 | av_free_packet(&packet); | |
247 | } | |
248 | end: | |
249 | avfilter_graph_free(&filter_graph); | |
250 | avcodec_close(dec_ctx); | |
251 | avformat_close_input(&fmt_ctx); | |
252 | av_frame_free(&frame); | |
253 | av_frame_free(&filt_frame); | |
254 | ||
255 | if (ret < 0 && ret != AVERROR_EOF) { | |
256 | fprintf(stderr, "Error occurred: %s\n", av_err2str(ret)); | |
257 | exit(1); | |
258 | } | |
259 | ||
260 | exit(0); | |
261 | } |