FFmpeg filter混音__FFmpeg

使用FFmpeg命令列將兩個音頻檔案合并為一個音頻檔案，命令列如下：

ffmpeg -i aa.mp3 -i bb.mp3 -filter_complex amix=inputs=2:duration=first:dropout_transition=2 -f mp3 remix.mp3

代碼實現：

extern "C"{#include "libavcodec/avcodec.h"#include "libavformat/avformat.h"#include "libavdevice/avdevice.h"#include "libavfilter/avfilter.h"#include "libavfilter/avfiltergraph.h"#include "libavfilter/buffersink.h"#include "libavfilter/buffersrc.h"#include "libavutil/audio_fifo.h"#include "libavutil/avutil.h"#include "libavutil/fifo.h"}#pragma comment(lib, "avcodec.lib")#pragma comment(lib, "avformat.lib")#pragma comment(lib, "avutil.lib")#pragma comment(lib, "avdevice.lib")#pragma comment(lib, "avfilter.lib")//#pragma comment(lib, "avfilter.lib")//#pragma comment(lib, "postproc.lib")//#pragma comment(lib, "swresample.lib")#pragma comment(lib, "swscale.lib")#include <windows.h>#include <conio.h>#include <time.h>enum CaptureState{    PREPARED,    RUNNING,    STOPPED,    FINISHED}; typedef struct BufferSourceContext {    const AVClass    *bscclass;    AVFifoBuffer     *fifo;    AVRational        time_base;     ///< time_base to set in the output link    AVRational        frame_rate;    ///< frame_rate to set in the output link    unsigned          nb_failed_requests;    unsigned          warning_limit;    /* video only */    int               w, h;    enum AVPixelFormat  pix_fmt;    AVRational        pixel_aspect;    char              *sws_param;    AVBufferRef *hw_frames_ctx;    /* audio only */    int sample_rate;    enum AVSampleFormat sample_fmt;    int channels;    uint64_t channel_layout;    char    *channel_layout_str;    int got_format_from_params;    int eof; } BufferSourceContext;AVFormatContext* _fmt_ctx_spk = NULL;AVFormatContext* _fmt_ctx_mic = NULL;AVFormatContext* _fmt_ctx_out = NULL;int _index_spk = -1;int _index_mic = -1;int _index_a_out = -1;AVFilterGraph* _filter_graph = NULL;AVFilterContext* _filter_ctx_src_spk = NULL;AVFilterContext* _filter_ctx_src_mic = NULL;AVFilterContext* _filter_ctx_sink = NULL;CaptureState _state = CaptureState::PREPARED;CRITICAL_SECTION _section_spk;CRITICAL_SECTION _section_mic;AVAudioFifo* _fifo_spk = NULL;AVAudioFifo* _fifo_mic = NULL;void InitRecorder(){    av_register_all();    avdevice_register_all();    avfilter_register_all();}int OpenSpeakerInput(char* inputForamt, char* url){    AVInputFormat* ifmt = av_find_input_format(inputForamt);    AVDictionary* opt1 = NULL;    av_dict_set(&opt1, "rtbufsize", "10M", 0);    int ret = 0;    ret = avformat_open_input(&_fmt_ctx_spk, url, ifmt, &opt1);    if (ret < 0)    {        printf("Speaker: failed to call avformat_open_input\n");        return -1;    }    ret = avformat_find_stream_info(_fmt_ctx_spk, NULL);    if (ret < 0)    {        printf("Speaker: failed to call avformat_find_stream_info\n");        return -1;    }    for (int i = 0; i < _fmt_ctx_spk->nb_streams; i++)    {        if (_fmt_ctx_spk->streams[i]->codec->codec_type == AVMEDIA_TYPE_AUDIO)        {            _index_spk = i;            break;        }    }    if (_index_spk < 0)    {        printf("Speaker: negative audio index\n");        return -1;    }    AVCodecContext* codec_ctx = _fmt_ctx_spk->streams[_index_spk]->codec;    AVCodec* codec = avcodec_find_decoder(codec_ctx->codec_id);    if (codec == NULL)    {        printf("Speaker: null audio decoder\n");        return -1;    }    ret = avcodec_open2(codec_ctx, codec, NULL);    if (ret < 0)    {        printf("Speaker: failed to call avcodec_open2\n");        return -1;    }    av_dump_format(_fmt_ctx_spk, _index_spk, url, 0);    return 0;}int OpenMicrophoneInput(char* inputForamt, char* url){    AVInputFormat* ifmt = av_find_input_format(inputForamt);    AVDictionary* opt1 = NULL;    av_dict_set(&opt1, "rtbufsize", "10M", 0);    int ret = 0;    ret = avformat_open_input(&_fmt_ctx_mic, url, ifmt, &opt1);    if (ret < 0)    {        printf("Microphone: failed to call avformat_open_input\n");        return -1;    }    ret = avformat_find_stream_info(_fmt_ctx_mic, NULL);    if (ret < 0)    {        printf("Microphone: failed to call avformat_find_stream_info\n");        return -1;    }    for (int i = 0; i < _fmt_ctx_mic->nb_streams; i++)    {        if (_fmt_ctx_mic->streams[i]->codec->codec_type == AVMEDIA_TYPE_AUDIO)        {            _index_mic = i;            break;        }    }    if (_index_mic < 0)    {        printf("Microphone: negative audio index\n");        return -1;    }    AVCodecContext* codec_ctx = _fmt_ctx_mic->streams[_index_mic]->codec;    AVCodec* codec = avcodec_find_decoder(codec_ctx->codec_id);    if (codec == NULL)    {        printf("Microphone: null audio decoder\n");        return -1;    }    ret = avcodec_open2(codec_ctx, codec, NULL);    if (ret < 0)    {        printf("Microphone: failed to call avcodec_open2\n");        return -1;    }    av_dump_format(_fmt_ctx_mic, _index_mic, url, 0);    return 0;}int OpenFileOutput(char* fileName){    int ret = 0;    ret = avformat_alloc_output_context2(&_fmt_ctx_out, NULL, NULL, fileName);    if (ret < 0)    {        printf("Mixer: failed to call avformat_alloc_output_context2\n");        return -1;    }    AVStream* stream_a = NULL;    stream_a = avformat_new_stream(_fmt_ctx_out, NULL);    if (stream_a == NULL)    {        printf("Mixer: failed to call avformat_new_stream\n");        return -1;    }    _index_a_out = 0;    stream_a->codec->codec_type = AVMEDIA_TYPE_AUDIO;    AVCodec* codec_mp3 = avcodec_find_encoder(AV_CODEC_ID_MP3);    stream_a->codec->codec = codec_mp3;    stream_a->codec->sample_rate = 16000;    stream_a->codec->channels = 1;    stream_a->codec->channel_layout = av_get_default_channel_layout(1);    stream_a->codec->sample_fmt = codec_mp3->sample_fmts[0];    stream_a->codec->bit_rate = 16000;    stream_a->codec->time_base.num = 1;    stream_a->codec->time_base.den = stream_a->codec->sample_rate;    stream_a->codec->codec_tag = 0;    if (_fmt_ctx_out->oformat->flags & AVFMT_GLOBALHEADER)        stream_a->codec->flags |= CODEC_FLAG_GLOBAL_HEADER;    if (avcodec_open2(stream_a->codec, stream_a->codec->codec, NULL) < 0)    {        printf("Mixer: failed to call avcodec_open2\n");        return -1;     }    if (!(_fmt_ctx_out->oformat->flags & AVFMT_NOFILE))    {        if (avio_open(&_fmt_ctx_out->pb, fileName, AVIO_FLAG_WRITE) < 0)        {            printf("Mixer: failed to call avio_open\n");            return -1;        }    }    if (avformat_write_header(_fmt_ctx_out, NULL) < 0)    {        printf("Mixer: failed to call avformat_write_header\n");        return -1;    }    bool b = (!_fmt_ctx_out->streams[0]->time_base.num && _fmt_ctx_out->streams[0]->codec->time_base.num);    av_dump_format(_fmt_ctx_out, _index_a_out, fileName, 1);    _fifo_spk = av_audio_fifo_alloc(_fmt_ctx_spk->streams[_index_spk]->codec->sample_fmt, _fmt_ctx_spk->streams[_index_spk]->codec->channels, 30*_fmt_ctx_spk->streams[_index_spk]->codec->frame_size);    _fifo_mic = av_audio_fifo_alloc(_fmt_ctx_mic->streams[_index_mic]->codec->sample_fmt, _fmt_ctx_mic->streams[_index_mic]->codec->channels, 30*_fmt_ctx_mic->streams[_index_spk]->codec->frame_size);    return 0;}int InitFilter(char* filter_desc){    char args_spk[5120];    char* pad_name_spk = "in0";    char args_mic[512];    char* pad_name_mic = "in1";    AVFilter* filter_src_spk = avfilter_get_by_name("abuffer");    AVFilter* filter_src_mic = avfilter_get_by_name("abuffer");    AVFilter* filter_sink = avfilter_get_by_name("abuffersink");    AVFilterInOut* filter_output_spk = avfilter_inout_alloc();    AVFilterInOut* filter_output_mic = avfilter_inout_alloc();    AVFilterInOut* filter_input = avfilter_inout_alloc();    _filter_graph = avfilter_graph_alloc();    sprintf_s(args_spk, sizeof(args_spk), "time_base=%d/%d:sample_rate=%d:sample_fmt=%s:channel_layout=0x%I64x",         _fmt_ctx_spk->streams[_index_spk]->codec->time_base.num,         _fmt_ctx_spk->streams[_index_spk]->codec->time_base.den,         _fmt_ctx_spk->streams[_index_spk]->codec->sample_rate,         av_get_sample_fmt_name(_fmt_ctx_spk->streams[_index_spk]->codec->sample_fmt),         _fmt_ctx_spk->streams[_index_spk]->codec->channel_layout);    sprintf_s(args_mic, sizeof(args_mic), "time_base=%d/%d:sample_rate=%d:sample_fmt=%s:channel_layout=0x%I64x",         _fmt_ctx_mic->streams[_index_mic]->codec->time_base.num,         _fmt_ctx_mic->streams[_index_mic]->codec->time_base.den,         _fmt_ctx_mic->streams[_index_mic]->codec->sample_rate,         av_get_sample_fmt_name(_fmt_ctx_mic->streams[_index_mic]->codec->sample_fmt),         _fmt_ctx_mic->streams[_index_mic]->codec->channel_layout);    //sprintf_s(args_spk, sizeof(args_spk), "time_base=%d/%d:sample_rate=%d:sample_fmt=%s:channel_layout=0x%I64x", _fmt_ctx_out->streams[_index_a_out]->codec->time_base.num, _fmt_ctx_out->streams[_index_a_out]->codec->time_base.den, _fmt_ctx_out->streams[_index_a_out]->codec->sample_rate, av_get_sample_fmt_name(_fmt_ctx_out->streams[_index_a_out]->codec->sample_fmt), _fmt_ctx_out->streams[_index_a_out]->codec->channel_layout);    //sprintf_s(args_mic, sizeof(args_mic), "time_base=%d/%d:sample_rate=%d:sample_fmt=%s:channel_layout=0x%I64x", _fmt_ctx_out->streams[_index_a_out]->codec->time_base.num, _fmt_ctx_out->streams[_index_a_out]->codec->time_base.den, _fmt_ctx_out->streams[_index_a_out]->codec->sample_rate, av_get_sample_fmt_name(_fmt_ctx_out->streams[_index_a_out]->codec->sample_fmt), _fmt_ctx_out->streams[_index_a_out]->codec->channel_layout);    int ret = 0;    ret = avfilter_graph_create_filter(&_filter_ctx_src_spk, filter_src_spk, pad_name_spk, args_spk, NULL, _filter_graph);    if (ret < 0)    {        printf("Filter: failed to call avfilter_graph_create_filter -- src spk\n");        return -1;    }    ret = avfilter_graph_create_filter(&_filter_ctx_src_mic, filter_src_mic, pad_name_mic, args_mic, NULL, _filter_graph);    if (ret < 0)    {        printf("Filter: failed to call avfilter_graph_create_filter -- src mic\n");        return -1;    }    ret = avfilter_graph_create_filter(&_filter_ctx_sink, filter_sink, "out", NULL, NULL, _filter_graph);    if (ret < 0)    {        printf("Filter: failed to call avfilter_graph_create_filter -- sink\n");        return -1;    }    AVCodecContext* encodec_ctx = _fmt_ctx_out->streams[_index_a_out]->codec;    ret = av_opt_set_bin(_filter_ctx_sink, "sample_fmts", (uint8_t*)&encodec_ctx->sample_fmt, sizeof(encodec_ctx->sample_fmt), AV_OPT_SEARCH_CHILDREN);    if (ret < 0)    {        printf("Filter: failed to call av_opt_set_bin -- sample_fmts\n");        return -1;    }    ret = av_opt_set_bin(_filter_ctx_sink, "channel_layouts", (uint8_t*)&encodec_ctx->channel_layout, sizeof(encodec_ctx->channel_layout), AV_OPT_SEARCH_CHILDREN);    if (ret < 0)    {        printf("Filter: failed to call av_opt_set_bin -- channel_layouts\n");        return -1;    }    ret = av_opt_set_bin(_filter_ctx_sink, "sample_rates", (uint8_t*)&encodec_ctx->sample_rate, sizeof(encodec_ctx->sample_rate), AV_OPT_SEARCH_CHILDREN);    if (ret < 0)    {        printf("Filter: failed to call av_opt_set_bin -- sample_rates\n");        return -1;    }    filter_output_spk->name = av_strdup(pad_name_spk);    filter_output_spk->filter_ctx = _filter_ctx_src_spk;    filter_output_spk->pad_idx = 0;    filter_output_spk->next = filter_output_mic;    filter_output_mic->name = av_strdup(pad_name_mic);    filter_output_mic->filter_ctx = _filter_ctx_src_mic;    filter_output_mic->pad_idx = 0;    filter_output_mic->next = NULL;    filter_input->name = av_strdup("out");    filter_input->filter_ctx = _filter_ctx_sink;    filter_input->pad_idx = 0;    filter_input->next = NULL;    AVFilterInOut* filter_outputs[2];    filter_outputs[0] = filter_output_spk;    filter_outputs[1] = filter_output_mic;    ret = avfilter_graph_parse_ptr(_filter_graph, filter_desc, &filter_input, filter_outputs, NULL);    if (ret < 0)    {        printf("Filter: failed to call avfilter_graph_parse_ptr\n");        return -1;    }    ret = avfilter_graph_config(_filter_graph, NULL);    if (ret < 0)    {        printf("Filter: failed to call avfilter_graph_config\n");        return -1;    }    avfilter_inout_free(&filter_input);    av_free(filter_src_spk);    av_free(filter_src_mic);    avfilter_inout_free(filter_outputs);    //av_free(filter_outputs);    char* temp = avfilter_graph_dump(_filter_graph, NULL);    printf("%s\n", temp);    return 0;}DWORD WINAPI SpeakerCapThreadProc(LPVOID lpParam){    AVFrame* pFrame = av_frame_alloc();    AVPacket packet;    av_init_packet(&packet);    int got_sound;    while (_state == CaptureState::RUNNING)    {        packet.data = NULL;        packet.size = 0;        if (av_read_frame(_fmt_ctx_spk, &packet) < 0)        {            continue;        }        if (packet.stream_index == _index_spk)        {            if (avcodec_decode_audio4(_fmt_ctx_spk->streams[_index_spk]->codec, pFrame, &got_sound, &packet) < 0)            {                break;            }            av_free_packet(&packet);            if (!got_sound)            {                continue;            }            int fifo_spk_space = av_audio_fifo_space(_fifo_spk);            while(fifo_spk_space < pFrame->nb_samples && _state == CaptureState::RUNNING)            {                Sleep(10);                printf("_fifo_spk full !\n");                fifo_spk_space = av_audio_fifo_space(_fifo_spk);            }            if (fifo_spk_space >= pFrame->nb_samples)            {                EnterCriticalSection(&_section_spk);                int nWritten = av_audio_fifo_write(_fifo_spk, (void**)pFrame->data, pFrame->nb_samples);                LeaveCriticalSection(&_section_spk);            }        }    }    av_frame_free(&pFrame);    return 0;}DWORD WINAPI MicrophoneCapThreadProc(LPVOID lpParam){    AVFrame* pFrame = av_frame_alloc();    AVPacket packet;    av_init_packet(&packet);    int got_sound;    while (_state == CaptureState::PREPARED)    {    }    while (_state == CaptureState::RUNNING)    {        packet.data = NULL;        packet.size = 0;        if (av_read_frame(_fmt_ctx_mic, &packet) < 0)        {            continue;        }        if (packet.stream_index == _index_mic)        {            if (avcodec_decode_audio4(_fmt_ctx_mic->streams[_index_mic]->codec, pFrame, &got_sound, &packet) < 0)            {                break;            }            av_free_packet(&packet);            if (!got_sound)            {                continue;            }            int fifo_mic_space = av_audio_fifo_space(_fifo_mic);            while(fifo_mic_space < pFrame->nb_samples && _state == CaptureState::RUNNING)            {                Sleep(10);                printf("_fifo_mic full !\n");                fifo_mic_space = av_audio_fifo_space(_fifo_mic);            }            if (fifo_mic_space >= pFrame->nb_samples)            {                EnterCriticalSection(&_section_mic);                int temp = av_audio_fifo_space(_fifo_mic);                int temp2 = pFrame->nb_samples;                int nWritten = av_audio_fifo_write(_fifo_mic, (void**)pFrame->data, pFrame->nb_samples);                LeaveCriticalSection(&_section_mic);            }        }    }    av_frame_free(&pFrame);    return 0;}int main(){    int ret = 0;    InitRecorder();    char fileName[128];    char* outFileType = ".mp3";    time_t rawtime;    tm* timeInfo;    time(&rawtime);    timeInfo = localtime(&rawtime);    sprintf_s(fileName, sizeof(fileName), "%d_%d_%d_%d_%d_%d%s",        timeInfo->tm_year + 1900, timeInfo->tm_mon + 1, timeInfo->tm_mday,        timeInfo->tm_hour, timeInfo->tm_min, timeInfo->tm_sec, outFileType);    char* filter_desc = "[in0][in1]amix=inputs=2[out]";    //ret = OpenSpeakerInput("dshow", "audio=virtual-audio-capturer");    ret = OpenSpeakerInput(NULL, "aa.mp3");    if (ret < 0)    {        goto Release;    }    //ret = OpenMicrophoneInput("dshow", "audio=External Microphone (Conexant S");    ret = OpenMicrophoneInput(NULL, "bb.mp3");    if (ret < 0)    {        goto Release;    }    ret = OpenFileOutput(fileName);    if (ret < 0)    {        goto Release;    }    ret = InitFilter(filter_desc);    if (ret < 0)    {        goto Release;    }    _state = CaptureState::RUNNING;    InitializeCriticalSection(&_section_spk);    InitializeCriticalSection(&_section_mic);    CreateThread(NULL, 0, SpeakerCapThreadProc, 0, 0, NULL);    CreateThread(NULL, 0, MicrophoneCapThreadProc, 0, 0, NULL);    int tmpFifoFailed = 0;    int64_t frame_count = 0;    while (_state != CaptureState::FINISHED)    {        if (_kbhit())        {            _state = CaptureState::STOPPED;            break;        }        else        {            int ret = 0;            AVFrame* pFrame_spk = av_frame_alloc();