CodecOpusOgg.h

#pragma once
 
#include "AudioTools/AudioCodecs/CodecOpus.h"
#include "AudioTools/AudioCodecs/ContainerOgg.h"
 
namespace audio_tools {
 
struct __attribute__((packed)) OpusOggHeader {
  char signature[8] = {'O', 'p', 'u', 's', 'H', 'e', 'a', 'd'};
  uint8_t version = 1;
  uint8_t channelCount = 0;
  uint16_t preSkip = 3840;
  uint32_t sampleRate = 0;
  int16_t outputGain = 0;
  uint8_t channelMappingFamily = 0;
};
 
struct __attribute__((packed)) OpusOggCommentHeader {
  char signature[8] = {'O', 'p', 'u', 's', 'T', 'a', 'g', 's'};
  uint32_t vendorStringLength = 8;
  char vendor[8] = "Arduino";
  uint32_t userCommentListLength = 0;
};
 
class OpusOggDecoder : public OggContainerDecoder {
 public:
  OpusOggDecoder() {
    p_codec = &dec;  // OpusAudioDecoder
    out.setDecoder(p_codec);
  };
 
  OpusSettings &config() { return dec.config(); }
 
  bool begin(OpusSettings settings) {
    OggContainerDecoder::begin();
    return dec.begin(settings);
  }
 
  bool begin() override {
    TRACED();
    OggContainerDecoder::begin();
    return dec.begin();
  }
 
  void end() override {
    TRACED();
    OggContainerDecoder::end();
    dec.end();
  }
 
 protected:
  OpusOggHeader header;
  OpusAudioDecoder dec;
 
  virtual void beginOfSegment(ogg_packet *op) override {
    LOGD("bos");
    if (op->packet == nullptr) return;
    if (strncmp("OpusHead", (char *)op->packet, 8) == 0) {
      memmove(&header, (char *)op->packet, sizeof(header));
      AudioInfo info = audioInfo();
      info.sample_rate = header.sampleRate;
      info.channels = header.channelCount;
      info.bits_per_sample = 16;
      info.logInfo();
      setAudioInfo(info);
    } else if (strncmp("OpusTags", (char *)op->packet, 8) == 0) {
      // not processed
    }
  }
};
 
class OpusOggWriter : public OggContainerOutput {
 protected:
  OpusOggHeader header;
  OpusOggCommentHeader comment;
  ogg_packet oh1;
 
  bool writeHeader() override {
    LOGI("writeHeader");
    bool result = true;
    header.sampleRate = cfg.sample_rate;
    header.channelCount = cfg.channels;
    // write header
    oh.packet = (uint8_t *)&header;
    oh.bytes = sizeof(header);
    oh.granulepos = 0;
    oh.packetno = packetno++;
    oh.b_o_s = true;
    oh.e_o_s = false;
    if (!writePacket(oh)) {
      result = false;
      LOGE("writePacket-header");
    }
 
    // write comment header
    oh1.packet = (uint8_t *)&comment;
    oh1.bytes = sizeof(comment);
    oh1.granulepos = 0;
    oh1.packetno = packetno++;
    oh1.b_o_s = true;
    oh1.e_o_s = false;
    if (!writePacket(oh1, OGGZ_FLUSH_AFTER)) {
      result = false;
      LOGE("writePacket-header1");
    }
    TRACED();
    return result;
  }
};
 
class OpusOggEncoder : public OggContainerEncoder {
 public:
  OpusOggEncoder() {
    setOggOutput(&ogg_writer);
    setEncoder(&enc);
  }
 
  const char *mime() override { return "audio/ogg;codecs=opus"; }
 
  OpusEncoderSettings &config() { return enc.config(); }
 
  uint32_t frameDurationUs() override {
    // Get frame duration from encoder settings
    int frameDurationMs = config().frame_sizes_ms_x2;
    uint32_t frameDurationUs = 20000;
    switch (frameDurationMs) {
      case OPUS_FRAMESIZE_2_5_MS:
        frameDurationUs = 2500;
        break;
      case OPUS_FRAMESIZE_5_MS:
        frameDurationUs = 5000;
        break;
      case OPUS_FRAMESIZE_10_MS:
        frameDurationUs = 10000;
        break;
      case OPUS_FRAMESIZE_20_MS:
        frameDurationUs = 20000;
        break;
    }
    return frameDurationUs;
  }
 
 protected:
  // use custom writer
  OpusOggWriter ogg_writer;
  // use opus encoder
  OpusAudioEncoder enc;
};
 
#include "AudioTools/Communication/RTSP/RTSPFormat.h"
 
}  // namespace audio_tools