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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; // f32le codec_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
