| /* |
| * copyright (c) 2013 Andrew Kelley |
| * |
| * This file is part of FFmpeg. |
| * |
| * FFmpeg is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Lesser General Public |
| * License as published by the Free Software Foundation; either |
| * version 2.1 of the License, or (at your option) any later version. |
| * |
| * FFmpeg is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Lesser General Public License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public |
| * License along with FFmpeg; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| */ |
| |
| /** |
| * @file |
| * libavfilter API usage example. |
| * |
| * @example filter_audio.c |
| * This example will generate a sine wave audio, |
| * pass it through a simple filter chain, and then compute the MD5 checksum of |
| * the output data. |
| * |
| * The filter chain it uses is: |
| * (input) -> abuffer -> volume -> aformat -> abuffersink -> (output) |
| * |
| * abuffer: This provides the endpoint where you can feed the decoded samples. |
| * volume: In this example we hardcode it to 0.90. |
| * aformat: This converts the samples to the samplefreq, channel layout, |
| * and sample format required by the audio device. |
| * abuffersink: This provides the endpoint where you can read the samples after |
| * they have passed through the filter chain. |
| */ |
| |
| #include <inttypes.h> |
| #include <math.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| |
| #include "libavutil/channel_layout.h" |
| #include "libavutil/md5.h" |
| #include "libavutil/mem.h" |
| #include "libavutil/opt.h" |
| #include "libavutil/samplefmt.h" |
| |
| #include "libavfilter/avfilter.h" |
| #include "libavfilter/buffersink.h" |
| #include "libavfilter/buffersrc.h" |
| |
| #define INPUT_SAMPLERATE 48000 |
| #define INPUT_FORMAT AV_SAMPLE_FMT_FLTP |
| #define INPUT_CHANNEL_LAYOUT AV_CH_LAYOUT_5POINT0 |
| |
| #define VOLUME_VAL 0.90 |
| |
| static int init_filter_graph(AVFilterGraph **graph, AVFilterContext **src, |
| AVFilterContext **sink) |
| { |
| AVFilterGraph *filter_graph; |
| AVFilterContext *abuffer_ctx; |
| AVFilter *abuffer; |
| AVFilterContext *volume_ctx; |
| AVFilter *volume; |
| AVFilterContext *aformat_ctx; |
| AVFilter *aformat; |
| AVFilterContext *abuffersink_ctx; |
| AVFilter *abuffersink; |
| |
| AVDictionary *options_dict = NULL; |
| uint8_t options_str[1024]; |
| uint8_t ch_layout[64]; |
| |
| int err; |
| |
| /* Create a new filtergraph, which will contain all the filters. */ |
| filter_graph = avfilter_graph_alloc(); |
| if (!filter_graph) { |
| fprintf(stderr, "Unable to create filter graph.\n"); |
| return AVERROR(ENOMEM); |
| } |
| |
| /* Create the abuffer filter; |
| * it will be used for feeding the data into the graph. */ |
| abuffer = avfilter_get_by_name("abuffer"); |
| if (!abuffer) { |
| fprintf(stderr, "Could not find the abuffer filter.\n"); |
| return AVERROR_FILTER_NOT_FOUND; |
| } |
| |
| abuffer_ctx = avfilter_graph_alloc_filter(filter_graph, abuffer, "src"); |
| if (!abuffer_ctx) { |
| fprintf(stderr, "Could not allocate the abuffer instance.\n"); |
| return AVERROR(ENOMEM); |
| } |
| |
| /* Set the filter options through the AVOptions API. */ |
| av_get_channel_layout_string(ch_layout, sizeof(ch_layout), 0, INPUT_CHANNEL_LAYOUT); |
| av_opt_set (abuffer_ctx, "channel_layout", ch_layout, AV_OPT_SEARCH_CHILDREN); |
| av_opt_set (abuffer_ctx, "sample_fmt", av_get_sample_fmt_name(INPUT_FORMAT), AV_OPT_SEARCH_CHILDREN); |
| av_opt_set_q (abuffer_ctx, "time_base", (AVRational){ 1, INPUT_SAMPLERATE }, AV_OPT_SEARCH_CHILDREN); |
| av_opt_set_int(abuffer_ctx, "sample_rate", INPUT_SAMPLERATE, AV_OPT_SEARCH_CHILDREN); |
| |
| /* Now initialize the filter; we pass NULL options, since we have already |
| * set all the options above. */ |
| err = avfilter_init_str(abuffer_ctx, NULL); |
| if (err < 0) { |
| fprintf(stderr, "Could not initialize the abuffer filter.\n"); |
| return err; |
| } |
| |
| /* Create volume filter. */ |
| volume = avfilter_get_by_name("volume"); |
| if (!volume) { |
| fprintf(stderr, "Could not find the volume filter.\n"); |
| return AVERROR_FILTER_NOT_FOUND; |
| } |
| |
| volume_ctx = avfilter_graph_alloc_filter(filter_graph, volume, "volume"); |
| if (!volume_ctx) { |
| fprintf(stderr, "Could not allocate the volume instance.\n"); |
| return AVERROR(ENOMEM); |
| } |
| |
| /* A different way of passing the options is as key/value pairs in a |
| * dictionary. */ |
| av_dict_set(&options_dict, "volume", AV_STRINGIFY(VOLUME_VAL), 0); |
| err = avfilter_init_dict(volume_ctx, &options_dict); |
| av_dict_free(&options_dict); |
| if (err < 0) { |
| fprintf(stderr, "Could not initialize the volume filter.\n"); |
| return err; |
| } |
| |
| /* Create the aformat filter; |
| * it ensures that the output is of the format we want. */ |
| aformat = avfilter_get_by_name("aformat"); |
| if (!aformat) { |
| fprintf(stderr, "Could not find the aformat filter.\n"); |
| return AVERROR_FILTER_NOT_FOUND; |
| } |
| |
| aformat_ctx = avfilter_graph_alloc_filter(filter_graph, aformat, "aformat"); |
| if (!aformat_ctx) { |
| fprintf(stderr, "Could not allocate the aformat instance.\n"); |
| return AVERROR(ENOMEM); |
| } |
| |
| /* A third way of passing the options is in a string of the form |
| * key1=value1:key2=value2.... */ |
| snprintf(options_str, sizeof(options_str), |
| "sample_fmts=%s:sample_rates=%d:channel_layouts=0x%"PRIx64, |
| av_get_sample_fmt_name(AV_SAMPLE_FMT_S16), 44100, |
| (uint64_t)AV_CH_LAYOUT_STEREO); |
| err = avfilter_init_str(aformat_ctx, options_str); |
| if (err < 0) { |
| av_log(NULL, AV_LOG_ERROR, "Could not initialize the aformat filter.\n"); |
| return err; |
| } |
| |
| /* Finally create the abuffersink filter; |
| * it will be used to get the filtered data out of the graph. */ |
| abuffersink = avfilter_get_by_name("abuffersink"); |
| if (!abuffersink) { |
| fprintf(stderr, "Could not find the abuffersink filter.\n"); |
| return AVERROR_FILTER_NOT_FOUND; |
| } |
| |
| abuffersink_ctx = avfilter_graph_alloc_filter(filter_graph, abuffersink, "sink"); |
| if (!abuffersink_ctx) { |
| fprintf(stderr, "Could not allocate the abuffersink instance.\n"); |
| return AVERROR(ENOMEM); |
| } |
| |
| /* This filter takes no options. */ |
| err = avfilter_init_str(abuffersink_ctx, NULL); |
| if (err < 0) { |
| fprintf(stderr, "Could not initialize the abuffersink instance.\n"); |
| return err; |
| } |
| |
| /* Connect the filters; |
| * in this simple case the filters just form a linear chain. */ |
| err = avfilter_link(abuffer_ctx, 0, volume_ctx, 0); |
| if (err >= 0) |
| err = avfilter_link(volume_ctx, 0, aformat_ctx, 0); |
| if (err >= 0) |
| err = avfilter_link(aformat_ctx, 0, abuffersink_ctx, 0); |
| if (err < 0) { |
| fprintf(stderr, "Error connecting filters\n"); |
| return err; |
| } |
| |
| /* Configure the graph. */ |
| err = avfilter_graph_config(filter_graph, NULL); |
| if (err < 0) { |
| av_log(NULL, AV_LOG_ERROR, "Error configuring the filter graph\n"); |
| return err; |
| } |
| |
| *graph = filter_graph; |
| *src = abuffer_ctx; |
| *sink = abuffersink_ctx; |
| |
| return 0; |
| } |
| |
| /* Do something useful with the filtered data: this simple |
| * example just prints the MD5 checksum of each plane to stdout. */ |
| static int process_output(struct AVMD5 *md5, AVFrame *frame) |
| { |
| int planar = av_sample_fmt_is_planar(frame->format); |
| int channels = av_get_channel_layout_nb_channels(frame->channel_layout); |
| int planes = planar ? channels : 1; |
| int bps = av_get_bytes_per_sample(frame->format); |
| int plane_size = bps * frame->nb_samples * (planar ? 1 : channels); |
| int i, j; |
| |
| for (i = 0; i < planes; i++) { |
| uint8_t checksum[16]; |
| |
| av_md5_init(md5); |
| av_md5_sum(checksum, frame->extended_data[i], plane_size); |
| |
| fprintf(stdout, "plane %d: 0x", i); |
| for (j = 0; j < sizeof(checksum); j++) |
| fprintf(stdout, "%02X", checksum[j]); |
| fprintf(stdout, "\n"); |
| } |
| fprintf(stdout, "\n"); |
| |
| return 0; |
| } |
| |
| /* Construct a frame of audio data to be filtered; |
| * this simple example just synthesizes a sine wave. */ |
| static int get_input(AVFrame *frame, int frame_num) |
| { |
| int err, i, j; |
| |
| #define FRAME_SIZE 1024 |
| |
| /* Set up the frame properties and allocate the buffer for the data. */ |
| frame->sample_rate = INPUT_SAMPLERATE; |
| frame->format = INPUT_FORMAT; |
| frame->channel_layout = INPUT_CHANNEL_LAYOUT; |
| frame->nb_samples = FRAME_SIZE; |
| frame->pts = frame_num * FRAME_SIZE; |
| |
| err = av_frame_get_buffer(frame, 0); |
| if (err < 0) |
| return err; |
| |
| /* Fill the data for each channel. */ |
| for (i = 0; i < 5; i++) { |
| float *data = (float*)frame->extended_data[i]; |
| |
| for (j = 0; j < frame->nb_samples; j++) |
| data[j] = sin(2 * M_PI * (frame_num + j) * (i + 1) / FRAME_SIZE); |
| } |
| |
| return 0; |
| } |
| |
| int main(int argc, char *argv[]) |
| { |
| struct AVMD5 *md5; |
| AVFilterGraph *graph; |
| AVFilterContext *src, *sink; |
| AVFrame *frame; |
| uint8_t errstr[1024]; |
| float duration; |
| int err, nb_frames, i; |
| |
| if (argc < 2) { |
| fprintf(stderr, "Usage: %s <duration>\n", argv[0]); |
| return 1; |
| } |
| |
| duration = atof(argv[1]); |
| nb_frames = duration * INPUT_SAMPLERATE / FRAME_SIZE; |
| if (nb_frames <= 0) { |
| fprintf(stderr, "Invalid duration: %s\n", argv[1]); |
| return 1; |
| } |
| |
| avfilter_register_all(); |
| |
| /* Allocate the frame we will be using to store the data. */ |
| frame = av_frame_alloc(); |
| if (!frame) { |
| fprintf(stderr, "Error allocating the frame\n"); |
| return 1; |
| } |
| |
| md5 = av_md5_alloc(); |
| if (!md5) { |
| fprintf(stderr, "Error allocating the MD5 context\n"); |
| return 1; |
| } |
| |
| /* Set up the filtergraph. */ |
| err = init_filter_graph(&graph, &src, &sink); |
| if (err < 0) { |
| fprintf(stderr, "Unable to init filter graph:"); |
| goto fail; |
| } |
| |
| /* the main filtering loop */ |
| for (i = 0; i < nb_frames; i++) { |
| /* get an input frame to be filtered */ |
| err = get_input(frame, i); |
| if (err < 0) { |
| fprintf(stderr, "Error generating input frame:"); |
| goto fail; |
| } |
| |
| /* Send the frame to the input of the filtergraph. */ |
| err = av_buffersrc_add_frame(src, frame); |
| if (err < 0) { |
| av_frame_unref(frame); |
| fprintf(stderr, "Error submitting the frame to the filtergraph:"); |
| goto fail; |
| } |
| |
| /* Get all the filtered output that is available. */ |
| while ((err = av_buffersink_get_frame(sink, frame)) >= 0) { |
| /* now do something with our filtered frame */ |
| err = process_output(md5, frame); |
| if (err < 0) { |
| fprintf(stderr, "Error processing the filtered frame:"); |
| goto fail; |
| } |
| av_frame_unref(frame); |
| } |
| |
| if (err == AVERROR(EAGAIN)) { |
| /* Need to feed more frames in. */ |
| continue; |
| } else if (err == AVERROR_EOF) { |
| /* Nothing more to do, finish. */ |
| break; |
| } else if (err < 0) { |
| /* An error occurred. */ |
| fprintf(stderr, "Error filtering the data:"); |
| goto fail; |
| } |
| } |
| |
| avfilter_graph_free(&graph); |
| av_frame_free(&frame); |
| av_freep(&md5); |
| |
| return 0; |
| |
| fail: |
| av_strerror(err, errstr, sizeof(errstr)); |
| fprintf(stderr, "%s\n", errstr); |
| return 1; |
| } |