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 41const char *filter_descr = "scale=78:24"; 42 43static AVFormatContext *fmt_ctx; 44static AVCodecContext *dec_ctx; 45AVFilterContext *buffersink_ctx; 46AVFilterContext *buffersrc_ctx; 47AVFilterGraph *filter_graph; 48static int video_stream_index = -1; 49static int64_t last_pts = AV_NOPTS_VALUE; 50 51static 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 85static 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 148end: 149 avfilter_inout_free(&inputs); 150 avfilter_inout_free(&outputs); 151 152 return ret; 153} 154 155static 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 186int 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 } 248end: 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} 262