[deb_ffmpeg.git] / ffmpeg / doc / examples / filtering_audio.c

/*
 * Copyright (c) 2010 Nicolas George
 * Copyright (c) 2011 Stefano Sabatini
 * Copyright (c) 2012 Clément Bœsch
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

/**
 * @file
 * API example for audio decoding and filtering
 * @example filtering_audio.c
 */

#include <unistd.h>

#include <libavcodec/avcodec.h>
#include <libavformat/avformat.h>
#include <libavfilter/avfiltergraph.h>
#include <libavfilter/avcodec.h>
#include <libavfilter/buffersink.h>
#include <libavfilter/buffersrc.h>
#include <libavutil/opt.h>

static const char *filter_descr = "aresample=8000,aformat=sample_fmts=s16:channel_layouts=mono";
static const char *player       = "ffplay -f s16le -ar 8000 -ac 1 -";

static AVFormatContext *fmt_ctx;
static AVCodecContext *dec_ctx;
AVFilterContext *buffersink_ctx;
AVFilterContext *buffersrc_ctx;
AVFilterGraph *filter_graph;
static int audio_stream_index = -1;

static int open_input_file(const char *filename)
{
    int ret;
    AVCodec *dec;

    if ((ret = avformat_open_input(&fmt_ctx, filename, NULL, NULL)) < 0) {
        av_log(NULL, AV_LOG_ERROR, "Cannot open input file\n");
        return ret;
    }

    if ((ret = avformat_find_stream_info(fmt_ctx, NULL)) < 0) {
        av_log(NULL, AV_LOG_ERROR, "Cannot find stream information\n");
        return ret;
    }

    /* select the audio stream */
    ret = av_find_best_stream(fmt_ctx, AVMEDIA_TYPE_AUDIO, -1, -1, &dec, 0);
    if (ret < 0) {
        av_log(NULL, AV_LOG_ERROR, "Cannot find a audio stream in the input file\n");
        return ret;
    }
    audio_stream_index = ret;
    dec_ctx = fmt_ctx->streams[audio_stream_index]->codec;
    av_opt_set_int(dec_ctx, "refcounted_frames", 1, 0);

    /* init the audio decoder */
    if ((ret = avcodec_open2(dec_ctx, dec, NULL)) < 0) {
        av_log(NULL, AV_LOG_ERROR, "Cannot open audio decoder\n");
        return ret;
    }

    return 0;
}

static int init_filters(const char *filters_descr)
{
    char args[512];
    int ret = 0;
    AVFilter *abuffersrc  = avfilter_get_by_name("abuffer");
    AVFilter *abuffersink = avfilter_get_by_name("abuffersink");
    AVFilterInOut *outputs = avfilter_inout_alloc();
    AVFilterInOut *inputs  = avfilter_inout_alloc();
    static const enum AVSampleFormat out_sample_fmts[] = { AV_SAMPLE_FMT_S16, -1 };
    static const int64_t out_channel_layouts[] = { AV_CH_LAYOUT_MONO, -1 };
    static const int out_sample_rates[] = { 8000, -1 };
    const AVFilterLink *outlink;
    AVRational time_base = fmt_ctx->streams[audio_stream_index]->time_base;

    filter_graph = avfilter_graph_alloc();
    if (!outputs || !inputs || !filter_graph) {
        ret = AVERROR(ENOMEM);
        goto end;
    }

    /* buffer audio source: the decoded frames from the decoder will be inserted here. */
    if (!dec_ctx->channel_layout)
        dec_ctx->channel_layout = av_get_default_channel_layout(dec_ctx->channels);
    snprintf(args, sizeof(args),
            "time_base=%d/%d:sample_rate=%d:sample_fmt=%s:channel_layout=0x%"PRIx64,
             time_base.num, time_base.den, dec_ctx->sample_rate,
             av_get_sample_fmt_name(dec_ctx->sample_fmt), dec_ctx->channel_layout);
    ret = avfilter_graph_create_filter(&buffersrc_ctx, abuffersrc, "in",
                                       args, NULL, filter_graph);
    if (ret < 0) {
        av_log(NULL, AV_LOG_ERROR, "Cannot create audio buffer source\n");
        goto end;
    }

    /* buffer audio sink: to terminate the filter chain. */
    ret = avfilter_graph_create_filter(&buffersink_ctx, abuffersink, "out",
                                       NULL, NULL, filter_graph);
    if (ret < 0) {
        av_log(NULL, AV_LOG_ERROR, "Cannot create audio buffer sink\n");
        goto end;
    }

    ret = av_opt_set_int_list(buffersink_ctx, "sample_fmts", out_sample_fmts, -1,
                              AV_OPT_SEARCH_CHILDREN);
    if (ret < 0) {
        av_log(NULL, AV_LOG_ERROR, "Cannot set output sample format\n");
        goto end;
    }

    ret = av_opt_set_int_list(buffersink_ctx, "channel_layouts", out_channel_layouts, -1,
                              AV_OPT_SEARCH_CHILDREN);
    if (ret < 0) {
        av_log(NULL, AV_LOG_ERROR, "Cannot set output channel layout\n");
        goto end;
    }

    ret = av_opt_set_int_list(buffersink_ctx, "sample_rates", out_sample_rates, -1,
                              AV_OPT_SEARCH_CHILDREN);
    if (ret < 0) {
        av_log(NULL, AV_LOG_ERROR, "Cannot set output sample rate\n");
        goto end;
    }

    /* Endpoints for the filter graph. */
    outputs->name       = av_strdup("in");
    outputs->filter_ctx = buffersrc_ctx;
    outputs->pad_idx    = 0;
    outputs->next       = NULL;

    inputs->name       = av_strdup("out");
    inputs->filter_ctx = buffersink_ctx;
    inputs->pad_idx    = 0;
    inputs->next       = NULL;

    if ((ret = avfilter_graph_parse_ptr(filter_graph, filters_descr,
                                        &inputs, &outputs, NULL)) < 0)
        goto end;

    if ((ret = avfilter_graph_config(filter_graph, NULL)) < 0)
        goto end;

    /* Print summary of the sink buffer
     * Note: args buffer is reused to store channel layout string */
    outlink = buffersink_ctx->inputs[0];
    av_get_channel_layout_string(args, sizeof(args), -1, outlink->channel_layout);
    av_log(NULL, AV_LOG_INFO, "Output: srate:%dHz fmt:%s chlayout:%s\n",
           (int)outlink->sample_rate,
           (char *)av_x_if_null(av_get_sample_fmt_name(outlink->format), "?"),
           args);

end:
    avfilter_inout_free(&inputs);
    avfilter_inout_free(&outputs);

    return ret;
}

static void print_frame(const AVFrame *frame)
{
    const int n = frame->nb_samples * av_get_channel_layout_nb_channels(av_frame_get_channel_layout(frame));
    const uint16_t *p     = (uint16_t*)frame->data[0];
    const uint16_t *p_end = p + n;

    while (p < p_end) {
        fputc(*p    & 0xff, stdout);
        fputc(*p>>8 & 0xff, stdout);
        p++;
    }
    fflush(stdout);
}

int main(int argc, char **argv)
{
    int ret;
    AVPacket packet0, packet;
    AVFrame *frame = av_frame_alloc();
    AVFrame *filt_frame = av_frame_alloc();
    int got_frame;

    if (!frame || !filt_frame) {
        perror("Could not allocate frame");
        exit(1);
    }
    if (argc != 2) {
        fprintf(stderr, "Usage: %s file | %s\n", argv[0], player);
        exit(1);
    }

    av_register_all();
    avfilter_register_all();

    if ((ret = open_input_file(argv[1])) < 0)
        goto end;
    if ((ret = init_filters(filter_descr)) < 0)
        goto end;

    /* read all packets */
    packet0.data = NULL;
    packet.data = NULL;
    while (1) {
        if (!packet0.data) {
            if ((ret = av_read_frame(fmt_ctx, &packet)) < 0)
                break;
            packet0 = packet;
        }

        if (packet.stream_index == audio_stream_index) {
            got_frame = 0;
            ret = avcodec_decode_audio4(dec_ctx, frame, &got_frame, &packet);
            if (ret < 0) {
                av_log(NULL, AV_LOG_ERROR, "Error decoding audio\n");
                continue;
            }
            packet.size -= ret;
            packet.data += ret;

            if (got_frame) {
                /* push the audio data from decoded frame into the filtergraph */
                if (av_buffersrc_add_frame_flags(buffersrc_ctx, frame, 0) < 0) {
                    av_log(NULL, AV_LOG_ERROR, "Error while feeding the audio filtergraph\n");
                    break;
                }

                /* pull filtered audio from the filtergraph */
                while (1) {
                    ret = av_buffersink_get_frame(buffersink_ctx, filt_frame);
                    if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
                        break;
                    if (ret < 0)
                        goto end;
                    print_frame(filt_frame);
                    av_frame_unref(filt_frame);
                }
            }

            if (packet.size <= 0)
                av_free_packet(&packet0);
        } else {
            /* discard non-wanted packets */
            av_free_packet(&packet0);
        }
    }
end:
    avfilter_graph_free(&filter_graph);
    avcodec_close(dec_ctx);
    avformat_close_input(&fmt_ctx);
    av_frame_free(&frame);
    av_frame_free(&filt_frame);

    if (ret < 0 && ret != AVERROR_EOF) {
        fprintf(stderr, "Error occurred: %s\n", av_err2str(ret));
        exit(1);
    }

    exit(0);
}
Commit	Line	Data
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	}