note

1.wav格式中，音频数据未经过压缩，直接封装即可

2.对于编码器的选择，应选择和pcm裸数据一致的编码器(本次实际不须编码)

version

#define LIBSWRESAMPLE_VERSION_MAJOR 2

#define LIBSWRESAMPLE_VERSION_MINOR 9

#define LIBSWRESAMPLE_VERSION_MICRO 100

#define LIBAVCODEC_VERSION_MINOR 31

#define LIBAVCODEC_VERSION_MICRO 102

code

void CFfmpegOps::MuxPCMToWAV(const char* pcm_file, const char* wav_file)
{const AVOutputFormat* out_fmt = nullptr;AVFormatContext* fmt_ctx = nullptr;const AVCodec* codec = nullptr;AVCodecContext* codec_ctx = nullptr;AVStream* avstream = nullptr;AVPacket* avpacket = nullptr;AVFrame* avframe = nullptr;int ret = -1;FILE* in_fp = nullptr;int sample_fmt_is_planar = 0;size_t n = 0;int frame_data_bytes = 0;codec = avcodec_find_encoder(AV_CODEC_ID_PCM_F32LE);if (!codec){printf("avcodec_find_encoder error\n");goto END;}codec_ctx = avcodec_alloc_context3(codec);if (!codec_ctx){printf("avcodec_alloc_context3 error\n");goto END;}codec_ctx->sample_fmt = AV_SAMPLE_FMT_FLT;  // f32lecodec_ctx->sample_rate = 44100;codec_ctx->channel_layout = AV_CH_LAYOUT_STEREO;codec_ctx->channels = av_get_channel_layout_nb_channels(codec_ctx->channel_layout);ret = avcodec_open2(codec_ctx, codec, nullptr);if (ret < 0){printf("avcodec_open2 error(%s)\n", GetFfmpegERR(ret));goto END;}printf("frame_size:%d\n", codec_ctx->frame_size);avframe = av_frame_alloc();if (!avframe){printf("av_frame_alloc error\n");goto END;}avframe->format = AV_SAMPLE_FMT_FLT;avframe->sample_rate = 44100;avframe->channel_layout = AV_CH_LAYOUT_STEREO;avframe->channels = av_get_channel_layout_nb_channels(avframe->channel_layout);avframe->nb_samples = 1024;ret = av_frame_get_buffer(avframe, 0);if (ret < 0){printf("av_frame_get_buffer error(%s)\n", GetFfmpegERR(ret));goto END;}ret = av_samples_get_buffer_size(nullptr, avframe->channels,avframe->nb_samples,(AVSampleFormat)(avframe->format),1);if (ret < 0){printf("av_samples_get_buffer_size error(%s)\n", GetFfmpegERR(ret));goto END;}frame_data_bytes = ret;avpacket = av_packet_alloc();if (!avpacket){printf("av_packet_alloc error\n");goto END;}in_fp = fopen(pcm_file, "rb");if (!in_fp){printf("fopen error\n");goto END;}ret = avformat_alloc_output_context2(&fmt_ctx, nullptr, nullptr, wav_file);if (ret < 0){printf("avformat_alloc_output_context2 error(%s)\n", GetFfmpegERR(ret));goto END;}out_fmt = fmt_ctx->oformat;avstream = avformat_new_stream(fmt_ctx, codec);if (!avstream){printf("avformat_new_stream error\n");goto END;}ret = avcodec_parameters_from_context(avstream->codecpar, codec_ctx);if (ret < 0){printf("avcodec_parameters_from_context error(%s)\n", GetFfmpegERR(ret));goto END;}ret = avio_open(&(fmt_ctx->pb), wav_file, AVIO_FLAG_READ_WRITE);if (ret < 0){printf("avio_open error(%s)\n", GetFfmpegERR(ret));goto END;}ret = avformat_write_header(fmt_ctx, nullptr);if (ret < 0){printf("avformat_write_header error(%s)\n", GetFfmpegERR(ret));goto END;}while (1){if (feof(in_fp)){break;}sample_fmt_is_planar = av_sample_fmt_is_planar((AVSampleFormat)(avframe->format));if (sample_fmt_is_planar){n = fread(avframe->data[0], sizeof(uint8_t), frame_data_bytes / 2, in_fp);if ((int)n != (frame_data_bytes / 2)){printf("n != (frame_data_bytes / 2)\n");}n = fread(avframe->data[1], sizeof(uint8_t), frame_data_bytes / 2, in_fp);if ((int)n != (frame_data_bytes / 2)){printf("n != (frame_data_bytes / 2)\n");}}else{n = fread(avframe->data[0], sizeof(uint8_t), frame_data_bytes, in_fp);if ((int)n != frame_data_bytes){printf("n != (frame_data_bytes)\n");}}ret = avcodec_send_frame(codec_ctx, avframe);if (ret < 0){if (ret == AVERROR(EAGAIN)){printf("read output first\n");}else{printf("avcodec_send_frame error(%s)\n", GetFfmpegERR(ret));break;}}while (1){ret = avcodec_receive_packet(codec_ctx, avpacket);if (ret < 0){if (ret == AVERROR(EAGAIN)){printf("send input first\n");break;}else{printf("avcodec_receive_packet error(%s)\n", GetFfmpegERR(ret));break;}}ret = av_write_frame(fmt_ctx, avpacket);if (ret < 0){printf("av_write_frame error(%s)\n", GetFfmpegERR(ret));av_packet_unref(avpacket);goto END;}av_packet_unref(avpacket);}}ret = avcodec_send_frame(codec_ctx, nullptr);while (1){ret = avcodec_receive_packet(codec_ctx, avpacket);if (ret < 0){if (ret == AVERROR(EAGAIN)){printf("send input first\n");break;}else{printf("avcodec_receive_packet error(%s)\n", GetFfmpegERR(ret));break;}}ret = av_write_frame(fmt_ctx, avpacket);if (ret < 0){printf("av_write_frame error(%s)\n", GetFfmpegERR(ret));av_packet_unref(avpacket);goto END;}av_packet_unref(avpacket);}ret = av_write_trailer(fmt_ctx);if (ret < 0){printf("av_write_trailer error(%s)\n", GetFfmpegERR(ret));goto END;}END:if (fmt_ctx){avformat_free_context(fmt_ctx);fmt_ctx = nullptr;}if (in_fp){fclose(in_fp);in_fp = nullptr;}if (avframe){av_frame_free(&avframe);avframe = nullptr;}if (avpacket){av_packet_free(&avpacket);avpacket = nullptr;}if (codec_ctx){avcodec_free_context(&codec_ctx);codec_ctx = nullptr;}
}

performance