/**********
This library is free software; you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License as published by the
Free Software Foundation; either version 3 of the License, or (at your
option) any later version. (See <http://www.gnu.org/copyleft/lesser.html>.)

This library is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for
more details.

You should have received a copy of the GNU Lesser General Public License
along with this library; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
**********/
// "liveMedia"
// Copyright (c) 1996-2020 Live Networks, Inc.  All rights reserved.
// 'Ogg' File Sink (recording a single media track only)
// Implementation

#include "OggFileSink.hh"
#include "OutputFile.hh"
#include "VorbisAudioRTPSource.hh" // for "parseVorbisOrTheoraConfigStr()"
#include "MPEG2TransportStreamMultiplexor.hh" // for calculateCRC()
#include "FramedSource.hh"

OggFileSink* OggFileSink
::createNew(UsageEnvironment& env, char const* fileName,
	    unsigned samplingFrequency, char const* configStr,
	    unsigned bufferSize, Boolean oneFilePerFrame) {
  do {
    FILE* fid;
    char const* perFrameFileNamePrefix;
    if (oneFilePerFrame) {
      // Create the fid for each frame
      fid = NULL;
      perFrameFileNamePrefix = fileName;
    } else {
      // Normal case: create the fid once
      fid = OpenOutputFile(env, fileName);
      if (fid == NULL) break;
      perFrameFileNamePrefix = NULL;
    }

    return new OggFileSink(env, fid, samplingFrequency, configStr, bufferSize, perFrameFileNamePrefix);
  } while (0);

  return NULL;
}

OggFileSink::OggFileSink(UsageEnvironment& env, FILE* fid,
			 unsigned samplingFrequency, char const* configStr,
			 unsigned bufferSize, char const* perFrameFileNamePrefix)
  : FileSink(env, fid, bufferSize, perFrameFileNamePrefix),
    fSamplingFrequency(samplingFrequency), fConfigStr(strDup(configStr)),
    fHaveWrittenFirstFrame(False), fHaveSeenEOF(False),
    fGranulePosition(0), fGranulePositionAdjustment(0), fPageSequenceNumber(0),
    fIsTheora(False), fGranuleIncrementPerFrame(1),
    fAltFrameSize(0), fAltNumTruncatedBytes(0) {
  fAltBuffer = new unsigned char[bufferSize];

  // Initialize our 'Ogg page header' array with constant values:
  u_int8_t* p = fPageHeaderBytes;
  *p++=0x4f; *p++=0x67; *p++=0x67; *p++=0x53; // bytes 0..3: 'capture_pattern': "OggS"
  *p++=0; // byte 4: 'stream_structure_version': 0
  *p++=0; // byte 5: 'header_type_flag': set on each write
  *p++=0; *p++=0; *p++=0; *p++=0; *p++=0; *p++=0; *p++=0; *p++=0;
      // bytes 6..13: 'granule_position': set on each write
  *p++=1; *p++=0; *p++=0; *p++=0; // bytes 14..17: 'bitstream_serial_number': 1
  *p++=0; *p++=0; *p++=0; *p++=0; // bytes 18..21: 'page_sequence_number': set on each write
  *p++=0; *p++=0; *p++=0; *p++=0; // bytes 22..25: 'CRC_checksum': set on each write
  *p=0; // byte 26: 'number_page_segments': set on each write
}

OggFileSink::~OggFileSink() {
  // We still have the previously-arrived frame, so write it to the file before we end:
  fHaveSeenEOF = True;
  OggFileSink::addData(fAltBuffer, fAltFrameSize, fAltPresentationTime);

  delete[] fAltBuffer;
  delete[] (char*)fConfigStr;
}

Boolean OggFileSink::continuePlaying() {
  // Identical to "FileSink::continuePlaying()",
  // except that we use our own 'on source closure' function:
  if (fSource == NULL) return False;

  fSource->getNextFrame(fBuffer, fBufferSize,
			FileSink::afterGettingFrame, this,
			ourOnSourceClosure, this);
  return True;
}

#define PAGE_DATA_MAX_SIZE (255*255)

void OggFileSink::addData(unsigned char const* data, unsigned dataSize,
			  struct timeval presentationTime) {
  if (dataSize == 0) return;

  // Set "fGranulePosition" for this frame:
  if (fIsTheora) {
    // Special case for Theora: "fGranulePosition" is supposed to be made up of a pair:
    //   (frame count to last key frame) | (frame count since last key frame)
    // However, because there appears to be no easy way to figure out which frames are key frames,
    // we just assume that all frames are key frames.
    if (!(data[0] >= 0x80 && data[0] <= 0x82)) { // for header pages, "fGranulePosition" remains 0
      fGranulePosition += fGranuleIncrementPerFrame;
    }
  } else {
    double ptDiff
      = (presentationTime.tv_sec - fFirstPresentationTime.tv_sec)
      + (presentationTime.tv_usec - fFirstPresentationTime.tv_usec)/1000000.0;
    int64_t newGranulePosition
      = (int64_t)(fSamplingFrequency*ptDiff) + fGranulePositionAdjustment;
    if (newGranulePosition < fGranulePosition) {
      // Update "fGranulePositionAdjustment" so that "fGranulePosition" remains monotonic
      fGranulePositionAdjustment += fGranulePosition - newGranulePosition;
    } else {
      fGranulePosition = newGranulePosition;
    }
  }

  // Write the frame to the file as a single Ogg 'page' (or perhaps as multiple pages
  // if it's too big for a single page).  We don't aggregate more than one frame within
  // an Ogg page because that's not legal for some headers, and because that would make
  // it difficult for us to properly set the 'eos' (end of stream) flag on the last page.

  // First, figure out how many pages to write here
  // (a page can contain no more than PAGE_DATA_MAX_SIZE bytes)
  unsigned numPagesToWrite = dataSize/PAGE_DATA_MAX_SIZE + 1;
      // Note that if "dataSize" is a integral multiple of PAGE_DATA_MAX_SIZE, there will
      // be an extra 0-size page at the end
  for (unsigned i = 0; i < numPagesToWrite; ++i) {
    // First, fill in the changeable parts of our 'page header' array;
    u_int8_t header_type_flag = 0x0;
    if (!fHaveWrittenFirstFrame && i == 0) {
      header_type_flag |= 0x02; // 'bos'
      fHaveWrittenFirstFrame = True; // for the future
    }
    if (i > 0) header_type_flag |= 0x01; // 'continuation'
    if (fHaveSeenEOF && i == numPagesToWrite-1) header_type_flag |= 0x04; // 'eos'
    fPageHeaderBytes[5] = header_type_flag;
    
    if (i < numPagesToWrite-1) {
      // For pages where the frame does not end, set 'granule_position' in the header to -1:
      fPageHeaderBytes[6] = fPageHeaderBytes[7] = fPageHeaderBytes[8] = fPageHeaderBytes[9] =
      fPageHeaderBytes[10] = fPageHeaderBytes[11] = fPageHeaderBytes[12] = fPageHeaderBytes[13]
	= 0xFF;
    } else {
      fPageHeaderBytes[6] = (u_int8_t)fGranulePosition;
      fPageHeaderBytes[7] = (u_int8_t)(fGranulePosition>>8);
      fPageHeaderBytes[8] = (u_int8_t)(fGranulePosition>>16);
      fPageHeaderBytes[9] = (u_int8_t)(fGranulePosition>>24);
      fPageHeaderBytes[10] = (u_int8_t)(fGranulePosition>>32);
      fPageHeaderBytes[11] = (u_int8_t)(fGranulePosition>>40);
      fPageHeaderBytes[12] = (u_int8_t)(fGranulePosition>>48);
      fPageHeaderBytes[13] = (u_int8_t)(fGranulePosition>>56);
    }

    fPageHeaderBytes[18] = (u_int8_t)fPageSequenceNumber;
    fPageHeaderBytes[19] = (u_int8_t)(fPageSequenceNumber>>8);
    fPageHeaderBytes[20] = (u_int8_t)(fPageSequenceNumber>>16);
    fPageHeaderBytes[21] = (u_int8_t)(fPageSequenceNumber>>24);
    ++fPageSequenceNumber;

    unsigned pageDataSize;
    u_int8_t number_page_segments;
    if (dataSize >= PAGE_DATA_MAX_SIZE) {
      pageDataSize = PAGE_DATA_MAX_SIZE;
      number_page_segments = 255;
    } else {
      pageDataSize = dataSize;
      number_page_segments = (pageDataSize+255)/255; // so that we don't end with a lacing of 255
    }
    fPageHeaderBytes[26] = number_page_segments;

    u_int8_t segment_table[255];
    for (unsigned j = 0; j < (unsigned)(number_page_segments-1); ++j) {
      segment_table[j] = 255;
    }
    segment_table[number_page_segments-1] = pageDataSize%255;

    // Compute the CRC from the 'page header' array, the 'segment_table', and the frame data:
    u_int32_t crc = 0;
    fPageHeaderBytes[22] = fPageHeaderBytes[23] = fPageHeaderBytes[24] = fPageHeaderBytes[25] = 0;
    crc = calculateCRC(fPageHeaderBytes, 27, 0);
    crc = calculateCRC(segment_table, number_page_segments, crc);
    crc = calculateCRC(data, pageDataSize, crc);
    fPageHeaderBytes[22] = (u_int8_t)crc;
    fPageHeaderBytes[23] = (u_int8_t)(crc>>8);
    fPageHeaderBytes[24] = (u_int8_t)(crc>>16);
    fPageHeaderBytes[25] = (u_int8_t)(crc>>24);

    // Then write out the 'page header' array:
    FileSink::addData(fPageHeaderBytes, 27, presentationTime);

    // Then write out the 'segment_table':
    FileSink::addData(segment_table, number_page_segments, presentationTime);

    // Then add frame data, to complete the page:
    FileSink::addData(data, pageDataSize, presentationTime);
    data += pageDataSize;
    dataSize -= pageDataSize;
  }
}

void OggFileSink::afterGettingFrame(unsigned frameSize, unsigned numTruncatedBytes, struct timeval presentationTime) {
  if (!fHaveWrittenFirstFrame) {
    fFirstPresentationTime = presentationTime;

    // If we have a 'config string' representing 'packed configuration headers'
    // ("identification", "comment", "setup"), unpack them and prepend them to the file:
    if (fConfigStr != NULL && fConfigStr[0] != '\0') {
      u_int8_t* identificationHdr; unsigned identificationHdrSize;
      u_int8_t* commentHdr; unsigned commentHdrSize;
      u_int8_t* setupHdr; unsigned setupHdrSize;
      u_int32_t identField;
      parseVorbisOrTheoraConfigStr(fConfigStr,
				   identificationHdr, identificationHdrSize,
				   commentHdr, commentHdrSize,
				   setupHdr, setupHdrSize,
				   identField);
      if (identificationHdrSize >= 42
	  && strncmp((const char*)&identificationHdr[1], "theora", 6) == 0) {
	// Hack for Theora video: Parse the "identification" hdr to get the "KFGSHIFT" parameter:
	fIsTheora = True;
	u_int8_t const KFGSHIFT = ((identificationHdr[40]&3)<<3) | (identificationHdr[41]>>5);
	fGranuleIncrementPerFrame = (u_int64_t)(1 << KFGSHIFT);
      }
      OggFileSink::addData(identificationHdr, identificationHdrSize, presentationTime);
      OggFileSink::addData(commentHdr, commentHdrSize, presentationTime);
      
      // Hack: Handle the "setup" header as if had arrived in the previous delivery, so it'll get
      // written properly below:
      if (setupHdrSize > fBufferSize) {
	fAltFrameSize = fBufferSize;
	fAltNumTruncatedBytes = setupHdrSize - fBufferSize;
      } else {
	fAltFrameSize = setupHdrSize;
	fAltNumTruncatedBytes = 0;
      }
      memmove(fAltBuffer, setupHdr, fAltFrameSize);
      fAltPresentationTime = presentationTime;
      
      delete[] identificationHdr;
      delete[] commentHdr;
      delete[] setupHdr;
    }
  }

  // Save this input frame for next time, and instead write the previous input frame now:
  unsigned char* tmpPtr = fBuffer; fBuffer = fAltBuffer; fAltBuffer = tmpPtr;
  unsigned prevFrameSize = fAltFrameSize; fAltFrameSize = frameSize;
  unsigned prevNumTruncatedBytes = fAltNumTruncatedBytes; fAltNumTruncatedBytes = numTruncatedBytes;
  struct timeval prevPresentationTime = fAltPresentationTime; fAltPresentationTime = presentationTime;

  // Call the parent class to complete the normal file write with the (previous) input frame:
  FileSink::afterGettingFrame(prevFrameSize, prevNumTruncatedBytes, prevPresentationTime);
}

void OggFileSink::ourOnSourceClosure(void* clientData) {
  ((OggFileSink*)clientData)->ourOnSourceClosure();
}

void OggFileSink::ourOnSourceClosure() {
  fHaveSeenEOF = True;

  // We still have the previously-arrived frame, so write it to the file before we end:
  OggFileSink::addData(fAltBuffer, fAltFrameSize, fAltPresentationTime);

  // Handle the closure for real:
  onSourceClosure();
}