| 1 | /* |
| 2 | * copyright (c) 2013 Andrew Kelley |
| 3 | * |
| 4 | * This file is part of FFmpeg. |
| 5 | * |
| 6 | * FFmpeg is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of the GNU Lesser General Public |
| 8 | * License as published by the Free Software Foundation; either |
| 9 | * version 2.1 of the License, or (at your option) any later version. |
| 10 | * |
| 11 | * FFmpeg is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 14 | * Lesser General Public License for more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU Lesser General Public |
| 17 | * License along with FFmpeg; if not, write to the Free Software |
| 18 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 19 | */ |
| 20 | |
| 21 | /** |
| 22 | * @file |
| 23 | * libavfilter API usage example. |
| 24 | * |
| 25 | * @example filter_audio.c |
| 26 | * This example will generate a sine wave audio, |
| 27 | * pass it through a simple filter chain, and then compute the MD5 checksum of |
| 28 | * the output data. |
| 29 | * |
| 30 | * The filter chain it uses is: |
| 31 | * (input) -> abuffer -> volume -> aformat -> abuffersink -> (output) |
| 32 | * |
| 33 | * abuffer: This provides the endpoint where you can feed the decoded samples. |
| 34 | * volume: In this example we hardcode it to 0.90. |
| 35 | * aformat: This converts the samples to the samplefreq, channel layout, |
| 36 | * and sample format required by the audio device. |
| 37 | * abuffersink: This provides the endpoint where you can read the samples after |
| 38 | * they have passed through the filter chain. |
| 39 | */ |
| 40 | |
| 41 | #include <inttypes.h> |
| 42 | #include <math.h> |
| 43 | #include <stdio.h> |
| 44 | #include <stdlib.h> |
| 45 | |
| 46 | #include "libavutil/channel_layout.h" |
| 47 | #include "libavutil/md5.h" |
| 48 | #include "libavutil/mem.h" |
| 49 | #include "libavutil/opt.h" |
| 50 | #include "libavutil/samplefmt.h" |
| 51 | |
| 52 | #include "libavfilter/avfilter.h" |
| 53 | #include "libavfilter/buffersink.h" |
| 54 | #include "libavfilter/buffersrc.h" |
| 55 | |
| 56 | #define INPUT_SAMPLERATE 48000 |
| 57 | #define INPUT_FORMAT AV_SAMPLE_FMT_FLTP |
| 58 | #define INPUT_CHANNEL_LAYOUT AV_CH_LAYOUT_5POINT0 |
| 59 | |
| 60 | #define VOLUME_VAL 0.90 |
| 61 | |
| 62 | static int init_filter_graph(AVFilterGraph **graph, AVFilterContext **src, |
| 63 | AVFilterContext **sink) |
| 64 | { |
| 65 | AVFilterGraph *filter_graph; |
| 66 | AVFilterContext *abuffer_ctx; |
| 67 | AVFilter *abuffer; |
| 68 | AVFilterContext *volume_ctx; |
| 69 | AVFilter *volume; |
| 70 | AVFilterContext *aformat_ctx; |
| 71 | AVFilter *aformat; |
| 72 | AVFilterContext *abuffersink_ctx; |
| 73 | AVFilter *abuffersink; |
| 74 | |
| 75 | AVDictionary *options_dict = NULL; |
| 76 | uint8_t options_str[1024]; |
| 77 | uint8_t ch_layout[64]; |
| 78 | |
| 79 | int err; |
| 80 | |
| 81 | /* Create a new filtergraph, which will contain all the filters. */ |
| 82 | filter_graph = avfilter_graph_alloc(); |
| 83 | if (!filter_graph) { |
| 84 | fprintf(stderr, "Unable to create filter graph.\n"); |
| 85 | return AVERROR(ENOMEM); |
| 86 | } |
| 87 | |
| 88 | /* Create the abuffer filter; |
| 89 | * it will be used for feeding the data into the graph. */ |
| 90 | abuffer = avfilter_get_by_name("abuffer"); |
| 91 | if (!abuffer) { |
| 92 | fprintf(stderr, "Could not find the abuffer filter.\n"); |
| 93 | return AVERROR_FILTER_NOT_FOUND; |
| 94 | } |
| 95 | |
| 96 | abuffer_ctx = avfilter_graph_alloc_filter(filter_graph, abuffer, "src"); |
| 97 | if (!abuffer_ctx) { |
| 98 | fprintf(stderr, "Could not allocate the abuffer instance.\n"); |
| 99 | return AVERROR(ENOMEM); |
| 100 | } |
| 101 | |
| 102 | /* Set the filter options through the AVOptions API. */ |
| 103 | av_get_channel_layout_string(ch_layout, sizeof(ch_layout), 0, INPUT_CHANNEL_LAYOUT); |
| 104 | av_opt_set (abuffer_ctx, "channel_layout", ch_layout, AV_OPT_SEARCH_CHILDREN); |
| 105 | av_opt_set (abuffer_ctx, "sample_fmt", av_get_sample_fmt_name(INPUT_FORMAT), AV_OPT_SEARCH_CHILDREN); |
| 106 | av_opt_set_q (abuffer_ctx, "time_base", (AVRational){ 1, INPUT_SAMPLERATE }, AV_OPT_SEARCH_CHILDREN); |
| 107 | av_opt_set_int(abuffer_ctx, "sample_rate", INPUT_SAMPLERATE, AV_OPT_SEARCH_CHILDREN); |
| 108 | |
| 109 | /* Now initialize the filter; we pass NULL options, since we have already |
| 110 | * set all the options above. */ |
| 111 | err = avfilter_init_str(abuffer_ctx, NULL); |
| 112 | if (err < 0) { |
| 113 | fprintf(stderr, "Could not initialize the abuffer filter.\n"); |
| 114 | return err; |
| 115 | } |
| 116 | |
| 117 | /* Create volume filter. */ |
| 118 | volume = avfilter_get_by_name("volume"); |
| 119 | if (!volume) { |
| 120 | fprintf(stderr, "Could not find the volume filter.\n"); |
| 121 | return AVERROR_FILTER_NOT_FOUND; |
| 122 | } |
| 123 | |
| 124 | volume_ctx = avfilter_graph_alloc_filter(filter_graph, volume, "volume"); |
| 125 | if (!volume_ctx) { |
| 126 | fprintf(stderr, "Could not allocate the volume instance.\n"); |
| 127 | return AVERROR(ENOMEM); |
| 128 | } |
| 129 | |
| 130 | /* A different way of passing the options is as key/value pairs in a |
| 131 | * dictionary. */ |
| 132 | av_dict_set(&options_dict, "volume", AV_STRINGIFY(VOLUME_VAL), 0); |
| 133 | err = avfilter_init_dict(volume_ctx, &options_dict); |
| 134 | av_dict_free(&options_dict); |
| 135 | if (err < 0) { |
| 136 | fprintf(stderr, "Could not initialize the volume filter.\n"); |
| 137 | return err; |
| 138 | } |
| 139 | |
| 140 | /* Create the aformat filter; |
| 141 | * it ensures that the output is of the format we want. */ |
| 142 | aformat = avfilter_get_by_name("aformat"); |
| 143 | if (!aformat) { |
| 144 | fprintf(stderr, "Could not find the aformat filter.\n"); |
| 145 | return AVERROR_FILTER_NOT_FOUND; |
| 146 | } |
| 147 | |
| 148 | aformat_ctx = avfilter_graph_alloc_filter(filter_graph, aformat, "aformat"); |
| 149 | if (!aformat_ctx) { |
| 150 | fprintf(stderr, "Could not allocate the aformat instance.\n"); |
| 151 | return AVERROR(ENOMEM); |
| 152 | } |
| 153 | |
| 154 | /* A third way of passing the options is in a string of the form |
| 155 | * key1=value1:key2=value2.... */ |
| 156 | snprintf(options_str, sizeof(options_str), |
| 157 | "sample_fmts=%s:sample_rates=%d:channel_layouts=0x%"PRIx64, |
| 158 | av_get_sample_fmt_name(AV_SAMPLE_FMT_S16), 44100, |
| 159 | (uint64_t)AV_CH_LAYOUT_STEREO); |
| 160 | err = avfilter_init_str(aformat_ctx, options_str); |
| 161 | if (err < 0) { |
| 162 | av_log(NULL, AV_LOG_ERROR, "Could not initialize the aformat filter.\n"); |
| 163 | return err; |
| 164 | } |
| 165 | |
| 166 | /* Finally create the abuffersink filter; |
| 167 | * it will be used to get the filtered data out of the graph. */ |
| 168 | abuffersink = avfilter_get_by_name("abuffersink"); |
| 169 | if (!abuffersink) { |
| 170 | fprintf(stderr, "Could not find the abuffersink filter.\n"); |
| 171 | return AVERROR_FILTER_NOT_FOUND; |
| 172 | } |
| 173 | |
| 174 | abuffersink_ctx = avfilter_graph_alloc_filter(filter_graph, abuffersink, "sink"); |
| 175 | if (!abuffersink_ctx) { |
| 176 | fprintf(stderr, "Could not allocate the abuffersink instance.\n"); |
| 177 | return AVERROR(ENOMEM); |
| 178 | } |
| 179 | |
| 180 | /* This filter takes no options. */ |
| 181 | err = avfilter_init_str(abuffersink_ctx, NULL); |
| 182 | if (err < 0) { |
| 183 | fprintf(stderr, "Could not initialize the abuffersink instance.\n"); |
| 184 | return err; |
| 185 | } |
| 186 | |
| 187 | /* Connect the filters; |
| 188 | * in this simple case the filters just form a linear chain. */ |
| 189 | err = avfilter_link(abuffer_ctx, 0, volume_ctx, 0); |
| 190 | if (err >= 0) |
| 191 | err = avfilter_link(volume_ctx, 0, aformat_ctx, 0); |
| 192 | if (err >= 0) |
| 193 | err = avfilter_link(aformat_ctx, 0, abuffersink_ctx, 0); |
| 194 | if (err < 0) { |
| 195 | fprintf(stderr, "Error connecting filters\n"); |
| 196 | return err; |
| 197 | } |
| 198 | |
| 199 | /* Configure the graph. */ |
| 200 | err = avfilter_graph_config(filter_graph, NULL); |
| 201 | if (err < 0) { |
| 202 | av_log(NULL, AV_LOG_ERROR, "Error configuring the filter graph\n"); |
| 203 | return err; |
| 204 | } |
| 205 | |
| 206 | *graph = filter_graph; |
| 207 | *src = abuffer_ctx; |
| 208 | *sink = abuffersink_ctx; |
| 209 | |
| 210 | return 0; |
| 211 | } |
| 212 | |
| 213 | /* Do something useful with the filtered data: this simple |
| 214 | * example just prints the MD5 checksum of each plane to stdout. */ |
| 215 | static int process_output(struct AVMD5 *md5, AVFrame *frame) |
| 216 | { |
| 217 | int planar = av_sample_fmt_is_planar(frame->format); |
| 218 | int channels = av_get_channel_layout_nb_channels(frame->channel_layout); |
| 219 | int planes = planar ? channels : 1; |
| 220 | int bps = av_get_bytes_per_sample(frame->format); |
| 221 | int plane_size = bps * frame->nb_samples * (planar ? 1 : channels); |
| 222 | int i, j; |
| 223 | |
| 224 | for (i = 0; i < planes; i++) { |
| 225 | uint8_t checksum[16]; |
| 226 | |
| 227 | av_md5_init(md5); |
| 228 | av_md5_sum(checksum, frame->extended_data[i], plane_size); |
| 229 | |
| 230 | fprintf(stdout, "plane %d: 0x", i); |
| 231 | for (j = 0; j < sizeof(checksum); j++) |
| 232 | fprintf(stdout, "%02X", checksum[j]); |
| 233 | fprintf(stdout, "\n"); |
| 234 | } |
| 235 | fprintf(stdout, "\n"); |
| 236 | |
| 237 | return 0; |
| 238 | } |
| 239 | |
| 240 | /* Construct a frame of audio data to be filtered; |
| 241 | * this simple example just synthesizes a sine wave. */ |
| 242 | static int get_input(AVFrame *frame, int frame_num) |
| 243 | { |
| 244 | int err, i, j; |
| 245 | |
| 246 | #define FRAME_SIZE 1024 |
| 247 | |
| 248 | /* Set up the frame properties and allocate the buffer for the data. */ |
| 249 | frame->sample_rate = INPUT_SAMPLERATE; |
| 250 | frame->format = INPUT_FORMAT; |
| 251 | frame->channel_layout = INPUT_CHANNEL_LAYOUT; |
| 252 | frame->nb_samples = FRAME_SIZE; |
| 253 | frame->pts = frame_num * FRAME_SIZE; |
| 254 | |
| 255 | err = av_frame_get_buffer(frame, 0); |
| 256 | if (err < 0) |
| 257 | return err; |
| 258 | |
| 259 | /* Fill the data for each channel. */ |
| 260 | for (i = 0; i < 5; i++) { |
| 261 | float *data = (float*)frame->extended_data[i]; |
| 262 | |
| 263 | for (j = 0; j < frame->nb_samples; j++) |
| 264 | data[j] = sin(2 * M_PI * (frame_num + j) * (i + 1) / FRAME_SIZE); |
| 265 | } |
| 266 | |
| 267 | return 0; |
| 268 | } |
| 269 | |
| 270 | int main(int argc, char *argv[]) |
| 271 | { |
| 272 | struct AVMD5 *md5; |
| 273 | AVFilterGraph *graph; |
| 274 | AVFilterContext *src, *sink; |
| 275 | AVFrame *frame; |
| 276 | uint8_t errstr[1024]; |
| 277 | float duration; |
| 278 | int err, nb_frames, i; |
| 279 | |
| 280 | if (argc < 2) { |
| 281 | fprintf(stderr, "Usage: %s <duration>\n", argv[0]); |
| 282 | return 1; |
| 283 | } |
| 284 | |
| 285 | duration = atof(argv[1]); |
| 286 | nb_frames = duration * INPUT_SAMPLERATE / FRAME_SIZE; |
| 287 | if (nb_frames <= 0) { |
| 288 | fprintf(stderr, "Invalid duration: %s\n", argv[1]); |
| 289 | return 1; |
| 290 | } |
| 291 | |
| 292 | avfilter_register_all(); |
| 293 | |
| 294 | /* Allocate the frame we will be using to store the data. */ |
| 295 | frame = av_frame_alloc(); |
| 296 | if (!frame) { |
| 297 | fprintf(stderr, "Error allocating the frame\n"); |
| 298 | return 1; |
| 299 | } |
| 300 | |
| 301 | md5 = av_md5_alloc(); |
| 302 | if (!md5) { |
| 303 | fprintf(stderr, "Error allocating the MD5 context\n"); |
| 304 | return 1; |
| 305 | } |
| 306 | |
| 307 | /* Set up the filtergraph. */ |
| 308 | err = init_filter_graph(&graph, &src, &sink); |
| 309 | if (err < 0) { |
| 310 | fprintf(stderr, "Unable to init filter graph:"); |
| 311 | goto fail; |
| 312 | } |
| 313 | |
| 314 | /* the main filtering loop */ |
| 315 | for (i = 0; i < nb_frames; i++) { |
| 316 | /* get an input frame to be filtered */ |
| 317 | err = get_input(frame, i); |
| 318 | if (err < 0) { |
| 319 | fprintf(stderr, "Error generating input frame:"); |
| 320 | goto fail; |
| 321 | } |
| 322 | |
| 323 | /* Send the frame to the input of the filtergraph. */ |
| 324 | err = av_buffersrc_add_frame(src, frame); |
| 325 | if (err < 0) { |
| 326 | av_frame_unref(frame); |
| 327 | fprintf(stderr, "Error submitting the frame to the filtergraph:"); |
| 328 | goto fail; |
| 329 | } |
| 330 | |
| 331 | /* Get all the filtered output that is available. */ |
| 332 | while ((err = av_buffersink_get_frame(sink, frame)) >= 0) { |
| 333 | /* now do something with our filtered frame */ |
| 334 | err = process_output(md5, frame); |
| 335 | if (err < 0) { |
| 336 | fprintf(stderr, "Error processing the filtered frame:"); |
| 337 | goto fail; |
| 338 | } |
| 339 | av_frame_unref(frame); |
| 340 | } |
| 341 | |
| 342 | if (err == AVERROR(EAGAIN)) { |
| 343 | /* Need to feed more frames in. */ |
| 344 | continue; |
| 345 | } else if (err == AVERROR_EOF) { |
| 346 | /* Nothing more to do, finish. */ |
| 347 | break; |
| 348 | } else if (err < 0) { |
| 349 | /* An error occurred. */ |
| 350 | fprintf(stderr, "Error filtering the data:"); |
| 351 | goto fail; |
| 352 | } |
| 353 | } |
| 354 | |
| 355 | avfilter_graph_free(&graph); |
| 356 | av_frame_free(&frame); |
| 357 | av_freep(&md5); |
| 358 | |
| 359 | return 0; |
| 360 | |
| 361 | fail: |
| 362 | av_strerror(err, errstr, sizeof(errstr)); |
| 363 | fprintf(stderr, "%s\n", errstr); |
| 364 | return 1; |
| 365 | } |