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2ba45a60 DM |
1 | /* |
2 | * Copyright (c) 2010 Nicolas George | |
3 | * Copyright (c) 2011 Stefano Sabatini | |
4 | * Copyright (c) 2012 Clément Bœsch | |
5 | * | |
6 | * Permission is hereby granted, free of charge, to any person obtaining a copy | |
7 | * of this software and associated documentation files (the "Software"), to deal | |
8 | * in the Software without restriction, including without limitation the rights | |
9 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell | |
10 | * copies of the Software, and to permit persons to whom the Software is | |
11 | * furnished to do so, subject to the following conditions: | |
12 | * | |
13 | * The above copyright notice and this permission notice shall be included in | |
14 | * all copies or substantial portions of the Software. | |
15 | * | |
16 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
17 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
18 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL | |
19 | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
20 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, | |
21 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN | |
22 | * THE SOFTWARE. | |
23 | */ | |
24 | ||
25 | /** | |
26 | * @file | |
27 | * API example for audio decoding and filtering | |
28 | * @example filtering_audio.c | |
29 | */ | |
30 | ||
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 | static const char *filter_descr = "aresample=8000,aformat=sample_fmts=s16:channel_layouts=mono"; | |
42 | static const char *player = "ffplay -f s16le -ar 8000 -ac 1 -"; | |
43 | ||
44 | static AVFormatContext *fmt_ctx; | |
45 | static AVCodecContext *dec_ctx; | |
46 | AVFilterContext *buffersink_ctx; | |
47 | AVFilterContext *buffersrc_ctx; | |
48 | AVFilterGraph *filter_graph; | |
49 | static int audio_stream_index = -1; | |
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 audio stream */ | |
67 | ret = av_find_best_stream(fmt_ctx, AVMEDIA_TYPE_AUDIO, -1, -1, &dec, 0); | |
68 | if (ret < 0) { | |
69 | av_log(NULL, AV_LOG_ERROR, "Cannot find a audio stream in the input file\n"); | |
70 | return ret; | |
71 | } | |
72 | audio_stream_index = ret; | |
73 | dec_ctx = fmt_ctx->streams[audio_stream_index]->codec; | |
74 | av_opt_set_int(dec_ctx, "refcounted_frames", 1, 0); | |
75 | ||
76 | /* init the audio decoder */ | |
77 | if ((ret = avcodec_open2(dec_ctx, dec, NULL)) < 0) { | |
78 | av_log(NULL, AV_LOG_ERROR, "Cannot open audio 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 *abuffersrc = avfilter_get_by_name("abuffer"); | |
90 | AVFilter *abuffersink = avfilter_get_by_name("abuffersink"); | |
91 | AVFilterInOut *outputs = avfilter_inout_alloc(); | |
92 | AVFilterInOut *inputs = avfilter_inout_alloc(); | |
93 | static const enum AVSampleFormat out_sample_fmts[] = { AV_SAMPLE_FMT_S16, -1 }; | |
94 | static const int64_t out_channel_layouts[] = { AV_CH_LAYOUT_MONO, -1 }; | |
95 | static const int out_sample_rates[] = { 8000, -1 }; | |
96 | const AVFilterLink *outlink; | |
97 | AVRational time_base = fmt_ctx->streams[audio_stream_index]->time_base; | |
98 | ||
99 | filter_graph = avfilter_graph_alloc(); | |
100 | if (!outputs || !inputs || !filter_graph) { | |
101 | ret = AVERROR(ENOMEM); | |
102 | goto end; | |
103 | } | |
104 | ||
105 | /* buffer audio source: the decoded frames from the decoder will be inserted here. */ | |
106 | if (!dec_ctx->channel_layout) | |
107 | dec_ctx->channel_layout = av_get_default_channel_layout(dec_ctx->channels); | |
108 | snprintf(args, sizeof(args), | |
109 | "time_base=%d/%d:sample_rate=%d:sample_fmt=%s:channel_layout=0x%"PRIx64, | |
110 | time_base.num, time_base.den, dec_ctx->sample_rate, | |
111 | av_get_sample_fmt_name(dec_ctx->sample_fmt), dec_ctx->channel_layout); | |
112 | ret = avfilter_graph_create_filter(&buffersrc_ctx, abuffersrc, "in", | |
113 | args, NULL, filter_graph); | |
114 | if (ret < 0) { | |
115 | av_log(NULL, AV_LOG_ERROR, "Cannot create audio buffer source\n"); | |
116 | goto end; | |
117 | } | |
118 | ||
119 | /* buffer audio sink: to terminate the filter chain. */ | |
120 | ret = avfilter_graph_create_filter(&buffersink_ctx, abuffersink, "out", | |
121 | NULL, NULL, filter_graph); | |
122 | if (ret < 0) { | |
123 | av_log(NULL, AV_LOG_ERROR, "Cannot create audio buffer sink\n"); | |
124 | goto end; | |
125 | } | |
126 | ||
127 | ret = av_opt_set_int_list(buffersink_ctx, "sample_fmts", out_sample_fmts, -1, | |
128 | AV_OPT_SEARCH_CHILDREN); | |
129 | if (ret < 0) { | |
130 | av_log(NULL, AV_LOG_ERROR, "Cannot set output sample format\n"); | |
131 | goto end; | |
132 | } | |
133 | ||
134 | ret = av_opt_set_int_list(buffersink_ctx, "channel_layouts", out_channel_layouts, -1, | |
135 | AV_OPT_SEARCH_CHILDREN); | |
136 | if (ret < 0) { | |
137 | av_log(NULL, AV_LOG_ERROR, "Cannot set output channel layout\n"); | |
138 | goto end; | |
139 | } | |
140 | ||
141 | ret = av_opt_set_int_list(buffersink_ctx, "sample_rates", out_sample_rates, -1, | |
142 | AV_OPT_SEARCH_CHILDREN); | |
143 | if (ret < 0) { | |
144 | av_log(NULL, AV_LOG_ERROR, "Cannot set output sample rate\n"); | |
145 | goto end; | |
146 | } | |
147 | ||
148 | /* Endpoints for the filter graph. */ | |
149 | outputs->name = av_strdup("in"); | |
150 | outputs->filter_ctx = buffersrc_ctx; | |
151 | outputs->pad_idx = 0; | |
152 | outputs->next = NULL; | |
153 | ||
154 | inputs->name = av_strdup("out"); | |
155 | inputs->filter_ctx = buffersink_ctx; | |
156 | inputs->pad_idx = 0; | |
157 | inputs->next = NULL; | |
158 | ||
159 | if ((ret = avfilter_graph_parse_ptr(filter_graph, filters_descr, | |
160 | &inputs, &outputs, NULL)) < 0) | |
161 | goto end; | |
162 | ||
163 | if ((ret = avfilter_graph_config(filter_graph, NULL)) < 0) | |
164 | goto end; | |
165 | ||
166 | /* Print summary of the sink buffer | |
167 | * Note: args buffer is reused to store channel layout string */ | |
168 | outlink = buffersink_ctx->inputs[0]; | |
169 | av_get_channel_layout_string(args, sizeof(args), -1, outlink->channel_layout); | |
170 | av_log(NULL, AV_LOG_INFO, "Output: srate:%dHz fmt:%s chlayout:%s\n", | |
171 | (int)outlink->sample_rate, | |
172 | (char *)av_x_if_null(av_get_sample_fmt_name(outlink->format), "?"), | |
173 | args); | |
174 | ||
175 | end: | |
176 | avfilter_inout_free(&inputs); | |
177 | avfilter_inout_free(&outputs); | |
178 | ||
179 | return ret; | |
180 | } | |
181 | ||
182 | static void print_frame(const AVFrame *frame) | |
183 | { | |
184 | const int n = frame->nb_samples * av_get_channel_layout_nb_channels(av_frame_get_channel_layout(frame)); | |
185 | const uint16_t *p = (uint16_t*)frame->data[0]; | |
186 | const uint16_t *p_end = p + n; | |
187 | ||
188 | while (p < p_end) { | |
189 | fputc(*p & 0xff, stdout); | |
190 | fputc(*p>>8 & 0xff, stdout); | |
191 | p++; | |
192 | } | |
193 | fflush(stdout); | |
194 | } | |
195 | ||
196 | int main(int argc, char **argv) | |
197 | { | |
198 | int ret; | |
199 | AVPacket packet0, packet; | |
200 | AVFrame *frame = av_frame_alloc(); | |
201 | AVFrame *filt_frame = av_frame_alloc(); | |
202 | int got_frame; | |
203 | ||
204 | if (!frame || !filt_frame) { | |
205 | perror("Could not allocate frame"); | |
206 | exit(1); | |
207 | } | |
208 | if (argc != 2) { | |
209 | fprintf(stderr, "Usage: %s file | %s\n", argv[0], player); | |
210 | exit(1); | |
211 | } | |
212 | ||
213 | av_register_all(); | |
214 | avfilter_register_all(); | |
215 | ||
216 | if ((ret = open_input_file(argv[1])) < 0) | |
217 | goto end; | |
218 | if ((ret = init_filters(filter_descr)) < 0) | |
219 | goto end; | |
220 | ||
221 | /* read all packets */ | |
222 | packet0.data = NULL; | |
223 | packet.data = NULL; | |
224 | while (1) { | |
225 | if (!packet0.data) { | |
226 | if ((ret = av_read_frame(fmt_ctx, &packet)) < 0) | |
227 | break; | |
228 | packet0 = packet; | |
229 | } | |
230 | ||
231 | if (packet.stream_index == audio_stream_index) { | |
232 | got_frame = 0; | |
233 | ret = avcodec_decode_audio4(dec_ctx, frame, &got_frame, &packet); | |
234 | if (ret < 0) { | |
235 | av_log(NULL, AV_LOG_ERROR, "Error decoding audio\n"); | |
236 | continue; | |
237 | } | |
238 | packet.size -= ret; | |
239 | packet.data += ret; | |
240 | ||
241 | if (got_frame) { | |
242 | /* push the audio data from decoded frame into the filtergraph */ | |
243 | if (av_buffersrc_add_frame_flags(buffersrc_ctx, frame, 0) < 0) { | |
244 | av_log(NULL, AV_LOG_ERROR, "Error while feeding the audio filtergraph\n"); | |
245 | break; | |
246 | } | |
247 | ||
248 | /* pull filtered audio from the filtergraph */ | |
249 | while (1) { | |
250 | ret = av_buffersink_get_frame(buffersink_ctx, filt_frame); | |
251 | if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF) | |
252 | break; | |
253 | if (ret < 0) | |
254 | goto end; | |
255 | print_frame(filt_frame); | |
256 | av_frame_unref(filt_frame); | |
257 | } | |
258 | } | |
259 | ||
260 | if (packet.size <= 0) | |
261 | av_free_packet(&packet0); | |
262 | } else { | |
263 | /* discard non-wanted packets */ | |
264 | av_free_packet(&packet0); | |
265 | } | |
266 | } | |
267 | end: | |
268 | avfilter_graph_free(&filter_graph); | |
269 | avcodec_close(dec_ctx); | |
270 | avformat_close_input(&fmt_ctx); | |
271 | av_frame_free(&frame); | |
272 | av_frame_free(&filt_frame); | |
273 | ||
274 | if (ret < 0 && ret != AVERROR_EOF) { | |
275 | fprintf(stderr, "Error occurred: %s\n", av_err2str(ret)); | |
276 | exit(1); | |
277 | } | |
278 | ||
279 | exit(0); | |
280 | } |