Subversion Repositories Kolibri OS

Rev

Blame | Last modification | View Log | RSS feed

  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.     /*
  149.      * Set the endpoints for the filter graph. The filter_graph will
  150.      * be linked to the graph described by filters_descr.
  151.      */
  152.  
  153.     /*
  154.      * The buffer source output must be connected to the input pad of
  155.      * the first filter described by filters_descr; since the first
  156.      * filter input label is not specified, it is set to "in" by
  157.      * default.
  158.      */
  159.     outputs->name       = av_strdup("in");
  160.     outputs->filter_ctx = buffersrc_ctx;
  161.     outputs->pad_idx    = 0;
  162.     outputs->next       = NULL;
  163.  
  164.     /*
  165.      * The buffer sink input must be connected to the output pad of
  166.      * the last filter described by filters_descr; since the last
  167.      * filter output label is not specified, it is set to "out" by
  168.      * default.
  169.      */
  170.     inputs->name       = av_strdup("out");
  171.     inputs->filter_ctx = buffersink_ctx;
  172.     inputs->pad_idx    = 0;
  173.     inputs->next       = NULL;
  174.  
  175.     if ((ret = avfilter_graph_parse_ptr(filter_graph, filters_descr,
  176.                                         &inputs, &outputs, NULL)) < 0)
  177.         goto end;
  178.  
  179.     if ((ret = avfilter_graph_config(filter_graph, NULL)) < 0)
  180.         goto end;
  181.  
  182.     /* Print summary of the sink buffer
  183.      * Note: args buffer is reused to store channel layout string */
  184.     outlink = buffersink_ctx->inputs[0];
  185.     av_get_channel_layout_string(args, sizeof(args), -1, outlink->channel_layout);
  186.     av_log(NULL, AV_LOG_INFO, "Output: srate:%dHz fmt:%s chlayout:%s\n",
  187.            (int)outlink->sample_rate,
  188.            (char *)av_x_if_null(av_get_sample_fmt_name(outlink->format), "?"),
  189.            args);
  190.  
  191. end:
  192.     avfilter_inout_free(&inputs);
  193.     avfilter_inout_free(&outputs);
  194.  
  195.     return ret;
  196. }
  197.  
  198. static void print_frame(const AVFrame *frame)
  199. {
  200.     const int n = frame->nb_samples * av_get_channel_layout_nb_channels(av_frame_get_channel_layout(frame));
  201.     const uint16_t *p     = (uint16_t*)frame->data[0];
  202.     const uint16_t *p_end = p + n;
  203.  
  204.     while (p < p_end) {
  205.         fputc(*p    & 0xff, stdout);
  206.         fputc(*p>>8 & 0xff, stdout);
  207.         p++;
  208.     }
  209.     fflush(stdout);
  210. }
  211.  
  212. int main(int argc, char **argv)
  213. {
  214.     int ret;
  215.     AVPacket packet0, packet;
  216.     AVFrame *frame = av_frame_alloc();
  217.     AVFrame *filt_frame = av_frame_alloc();
  218.     int got_frame;
  219.  
  220.     if (!frame || !filt_frame) {
  221.         perror("Could not allocate frame");
  222.         exit(1);
  223.     }
  224.     if (argc != 2) {
  225.         fprintf(stderr, "Usage: %s file | %s\n", argv[0], player);
  226.         exit(1);
  227.     }
  228.  
  229.     av_register_all();
  230.     avfilter_register_all();
  231.  
  232.     if ((ret = open_input_file(argv[1])) < 0)
  233.         goto end;
  234.     if ((ret = init_filters(filter_descr)) < 0)
  235.         goto end;
  236.  
  237.     /* read all packets */
  238.     packet0.data = NULL;
  239.     packet.data = NULL;
  240.     while (1) {
  241.         if (!packet0.data) {
  242.             if ((ret = av_read_frame(fmt_ctx, &packet)) < 0)
  243.                 break;
  244.             packet0 = packet;
  245.         }
  246.  
  247.         if (packet.stream_index == audio_stream_index) {
  248.             got_frame = 0;
  249.             ret = avcodec_decode_audio4(dec_ctx, frame, &got_frame, &packet);
  250.             if (ret < 0) {
  251.                 av_log(NULL, AV_LOG_ERROR, "Error decoding audio\n");
  252.                 continue;
  253.             }
  254.             packet.size -= ret;
  255.             packet.data += ret;
  256.  
  257.             if (got_frame) {
  258.                 /* push the audio data from decoded frame into the filtergraph */
  259.                 if (av_buffersrc_add_frame_flags(buffersrc_ctx, frame, 0) < 0) {
  260.                     av_log(NULL, AV_LOG_ERROR, "Error while feeding the audio filtergraph\n");
  261.                     break;
  262.                 }
  263.  
  264.                 /* pull filtered audio from the filtergraph */
  265.                 while (1) {
  266.                     ret = av_buffersink_get_frame(buffersink_ctx, filt_frame);
  267.                     if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
  268.                         break;
  269.                     if (ret < 0)
  270.                         goto end;
  271.                     print_frame(filt_frame);
  272.                     av_frame_unref(filt_frame);
  273.                 }
  274.             }
  275.  
  276.             if (packet.size <= 0)
  277.                 av_free_packet(&packet0);
  278.         } else {
  279.             /* discard non-wanted packets */
  280.             av_free_packet(&packet0);
  281.         }
  282.     }
  283. end:
  284.     avfilter_graph_free(&filter_graph);
  285.     avcodec_close(dec_ctx);
  286.     avformat_close_input(&fmt_ctx);
  287.     av_frame_free(&frame);
  288.     av_frame_free(&filt_frame);
  289.  
  290.     if (ret < 0 && ret != AVERROR_EOF) {
  291.         fprintf(stderr, "Error occurred: %s\n", av_err2str(ret));
  292.         exit(1);
  293.     }
  294.  
  295.     exit(0);
  296. }
  297.