/**

 * FreeRDP: A Remote Desktop Protocol Implementation

 * Digital Sound Processing

 *

 * Copyright 2010-2011 Vic Lee

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

#include <freerdp/config.h>

#include <winpr/assert.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <winpr/crt.h>

#include <freerdp/types.h>

#include <freerdp/log.h>

#include <freerdp/codec/dsp.h>

#if !defined(WITH_DSP_FFMPEG)

#if defined(WITH_GSM)

#include <gsm/gsm.h>

#endif

#if defined(WITH_LAME)

#include <lame/lame.h>

#endif

#if defined(WITH_OPUS)

#include <opus/opus.h>

#define OPUS_MAX_FRAMES 5760

#endif

#if defined(WITH_FAAD2)

#include <neaacdec.h>

#endif

#if defined(WITH_FAAC)

#include <faac.h>

#endif

#if defined(WITH_SOXR)

#include <soxr.h>

#endif

#else

#include "dsp_ffmpeg.h"

#endif

#define TAG FREERDP_TAG("dsp")

#if !defined(WITH_DSP_FFMPEG)

typedef union

{

  struct

  {

    size_t packet_size;

    INT16 last_sample[2];

    INT16 last_step[2];

  } ima;

  struct

  {

    BYTE predictor[2];

    INT32 delta[2];

    INT32 sample1[2];

    INT32 sample2[2];

  } ms;

} ADPCM;

struct S_FREERDP_DSP_CONTEXT

{

  BOOL encoder;

  ADPCM adpcm;

  AUDIO_FORMAT format;

  wStream* channelmix;

  wStream* resample;

  wStream* buffer;

#if defined(WITH_GSM)

  gsm gsm;

#endif

#if defined(WITH_LAME)

  lame_t lame;

  hip_t hip;

#endif

#if defined(WITH_OPUS)

  OpusDecoder* opus_decoder;

  OpusEncoder* opus_encoder;

#endif

#if defined(WITH_FAAD2)

  NeAACDecHandle faad;

  BOOL faadSetup;

#endif

#if defined(WITH_FAAC)

  faacEncHandle faac;

  unsigned long faacInputSamples;

  unsigned long faacMaxOutputBytes;

#endif

#if defined(WITH_SOXR)

  soxr_t sox;

#endif

};

#if defined(WITH_OPUS)

static BOOL opus_is_valid_samplerate(const AUDIO_FORMAT* format)

{

  WINPR_ASSERT(format);

  switch (format->nSamplesPerSec)

  {

    case 8000:

    case 12000:

    case 16000:

    case 24000:

    case 48000:

      return TRUE;

    default:

      return FALSE;

  }

}

#endif

static INT16 read_int16(const BYTE* src)

{

  return (INT16)(src[0] | (src[1] << 8));

}

static BOOL freerdp_dsp_channel_mix(FREERDP_DSP_CONTEXT* context, const BYTE* src, size_t size,

                                    const AUDIO_FORMAT* srcFormat, const BYTE** data,

                                    size_t* length)

{

  UINT32 bpp;

  size_t samples;

  if (!context || !data || !length)

    return FALSE;

  if (srcFormat->wFormatTag != WAVE_FORMAT_PCM)

    return FALSE;

  bpp = srcFormat->wBitsPerSample > 8 ? 2 : 1;

  samples = size / bpp / srcFormat->nChannels;

  if (context->format.nChannels == srcFormat->nChannels)

  {

    *data = src;

    *length = size;

    return TRUE;

  }

  Stream_SetPosition(context->channelmix, 0);

  /* Destination has more channels than source */

  if (context->format.nChannels > srcFormat->nChannels)

  {

    switch (srcFormat->nChannels)

    {

      case 1:

        if (!Stream_EnsureCapacity(context->channelmix, size * 2))

          return FALSE;

        for (size_t x = 0; x < samples; x++)

        {

          for (size_t y = 0; y < bpp; y++)

            Stream_Write_UINT8(context->channelmix, src[x * bpp + y]);

          for (size_t y = 0; y < bpp; y++)

            Stream_Write_UINT8(context->channelmix, src[x * bpp + y]);

        }

        Stream_SealLength(context->channelmix);

        *data = Stream_Buffer(context->channelmix);

        *length = Stream_Length(context->channelmix);

        return TRUE;

      case 2:  /* We only support stereo, so we can not handle this case. */

      default: /* Unsupported number of channels */

        return FALSE;

    }

  }

  /* Destination has less channels than source */

  switch (srcFormat->nChannels)

  {

    case 2:

      if (!Stream_EnsureCapacity(context->channelmix, size / 2))

        return FALSE;

      /* Simply drop second channel.

       * TODO: Calculate average */

      for (size_t x = 0; x < samples; x++)

      {

        for (size_t y = 0; y < bpp; y++)

          Stream_Write_UINT8(context->channelmix, src[2 * x * bpp + y]);

      }

      Stream_SealLength(context->channelmix);

      *data = Stream_Buffer(context->channelmix);

      *length = Stream_Length(context->channelmix);

      return TRUE;

    case 1:  /* Invalid, do we want to use a 0 channel sound? */

    default: /* Unsupported number of channels */

      return FALSE;

  }

  return FALSE;

}

/**

 * Microsoft Multimedia Standards Update

 * http://download.microsoft.com/download/9/8/6/9863C72A-A3AA-4DDB-B1BA-CA8D17EFD2D4/RIFFNEW.pdf

 */

static BOOL freerdp_dsp_resample(FREERDP_DSP_CONTEXT* context, const BYTE* src, size_t size,

                                 const AUDIO_FORMAT* srcFormat, const BYTE** data, size_t* length)

{

#if defined(WITH_SOXR)

  soxr_error_t error;

  size_t idone, odone;

  size_t sframes, rframes;

  size_t rsize;

  size_t sbytes, rbytes;

  size_t dstChannels;

  size_t srcChannels;

  size_t srcBytesPerFrame, dstBytesPerFrame;

#endif

  AUDIO_FORMAT format;

  if (srcFormat->wFormatTag != WAVE_FORMAT_PCM)

  {

    WLog_ERR(TAG, "requires %s for sample input, got %s",

             audio_format_get_tag_string(WAVE_FORMAT_PCM),

             audio_format_get_tag_string(srcFormat->wFormatTag));

    return FALSE;

  }

  /* We want to ignore differences of source and destination format. */

  format = *srcFormat;

  format.wFormatTag = WAVE_FORMAT_UNKNOWN;

  format.wBitsPerSample = 0;

  if (audio_format_compatible(&format, &context->format))

  {

    *data = src;

    *length = size;

    return TRUE;

  }

#if defined(WITH_SOXR)

  srcBytesPerFrame = (srcFormat->wBitsPerSample > 8) ? 2 : 1;

  dstBytesPerFrame = (context->format.wBitsPerSample > 8) ? 2 : 1;

  srcChannels = srcFormat->nChannels;

  dstChannels = context->format.nChannels;

  sbytes = srcChannels * srcBytesPerFrame;

  sframes = size / sbytes;

  rbytes = dstBytesPerFrame * dstChannels;

  /* Integer rounding correct division */

  rframes = (sframes * context->format.nSamplesPerSec + (srcFormat->nSamplesPerSec + 1) / 2) /

            srcFormat->nSamplesPerSec;

  rsize = rframes * rbytes;

  if (!Stream_EnsureCapacity(context->resample, rsize))

    return FALSE;

  error = soxr_process(context->sox, src, sframes, &idone, Stream_Buffer(context->resample),

                       Stream_Capacity(context->resample) / rbytes, &odone);

  Stream_SetLength(context->resample, odone * rbytes);

  *data = Stream_Buffer(context->resample);

  *length = Stream_Length(context->resample);

  return (error == 0) ? TRUE : FALSE;

#else

  WLog_ERR(TAG, "Missing resample support, recompile -DWITH_SOXR=ON or -DWITH_DSP_FFMPEG=ON");

  return FALSE;

#endif

}

/**

 * Microsoft IMA ADPCM specification:

 *

 * http://wiki.multimedia.cx/index.php?title=Microsoft_IMA_ADPCM

 * http://wiki.multimedia.cx/index.php?title=IMA_ADPCM

 */

static const INT16 ima_step_index_table[] = {

  -1, -1, -1, -1, 2, 4, 6, 8, -1, -1, -1, -1, 2, 4, 6, 8

};

static const INT16 ima_step_size_table[] = {

  7,     8,     9,     10,    11,    12,    13,    14,    16,    17,    19,   21,    23,

  25,    28,    31,    34,    37,    41,    45,    50,    55,    60,    66,   73,    80,

  88,    97,    107,   118,   130,   143,   157,   173,   190,   209,   230,  253,   279,

  307,   337,   371,   408,   449,   494,   544,   598,   658,   724,   796,  876,   963,

  1060,  1166,  1282,  1411,  1552,  1707,  1878,  2066,  2272,  2499,  2749, 3024,  3327,

  3660,  4026,  4428,  4871,  5358,  5894,  6484,  7132,  7845,  8630,  9493, 10442, 11487,

  12635, 13899, 15289, 16818, 18500, 20350, 22385, 24623, 27086, 29794, 32767

};

static UINT16 dsp_decode_ima_adpcm_sample(ADPCM* adpcm, unsigned int channel, BYTE sample)

{

  INT32 ss;

  INT32 d;

  ss = ima_step_size_table[adpcm->ima.last_step[channel]];

  d = (ss >> 3);

  if (sample & 1)

    d += (ss >> 2);

  if (sample & 2)

    d += (ss >> 1);

  if (sample & 4)

    d += ss;

  if (sample & 8)

    d = -d;

  d += adpcm->ima.last_sample[channel];

  if (d < -32768)

    d = -32768;

  else if (d > 32767)

    d = 32767;

  adpcm->ima.last_sample[channel] = (INT16)d;

  adpcm->ima.last_step[channel] += ima_step_index_table[sample];

  if (adpcm->ima.last_step[channel] < 0)

    adpcm->ima.last_step[channel] = 0;

  else if (adpcm->ima.last_step[channel] > 88)

    adpcm->ima.last_step[channel] = 88;

  return (UINT16)d;

}

static BOOL freerdp_dsp_decode_ima_adpcm(FREERDP_DSP_CONTEXT* context, const BYTE* src, size_t size,

                                         wStream* out)

{

  BYTE sample;

  UINT16 decoded;

  size_t out_size = size * 4;

  UINT32 channel;

  const UINT32 block_size = context->format.nBlockAlign;

  const UINT32 channels = context->format.nChannels;

  if (!Stream_EnsureCapacity(out, out_size))

    return FALSE;

  while (size > 0)

  {

    if (size % block_size == 0)

    {

      context->adpcm.ima.last_sample[0] =

          (INT16)(((UINT16)(*src)) | (((UINT16)(*(src + 1))) << 8));

      context->adpcm.ima.last_step[0] = (INT16)(*(src + 2));

      src += 4;

      size -= 4;

      out_size -= 16;

      if (channels > 1)

      {

        context->adpcm.ima.last_sample[1] =

            (INT16)(((UINT16)(*src)) | (((UINT16)(*(src + 1))) << 8));

        context->adpcm.ima.last_step[1] = (INT16)(*(src + 2));

        src += 4;

        size -= 4;

        out_size -= 16;

      }

    }

    if (channels > 1)

    {

      for (size_t i = 0; i < 8; i++)

      {

        BYTE* dst = Stream_Pointer(out);

        channel = (i < 4 ? 0 : 1);

        sample = ((*src) & 0x0f);

        decoded = dsp_decode_ima_adpcm_sample(&context->adpcm, channel, sample);

        dst[((i & 3) << 3) + (channel << 1)] = (decoded & 0xFF);

        dst[((i & 3) << 3) + (channel << 1) + 1] = (decoded >> 8);

        sample = ((*src) >> 4);

        decoded = dsp_decode_ima_adpcm_sample(&context->adpcm, channel, sample);

        dst[((i & 3) << 3) + (channel << 1) + 4] = (decoded & 0xFF);

        dst[((i & 3) << 3) + (channel << 1) + 5] = (decoded >> 8);

        src++;

      }

      if (!Stream_SafeSeek(out, 32))

        return FALSE;

      size -= 8;

    }

    else

    {

      BYTE* dst = Stream_Pointer(out);

      if (!Stream_SafeSeek(out, 4))

        return FALSE;

      sample = ((*src) & 0x0f);

      decoded = dsp_decode_ima_adpcm_sample(&context->adpcm, 0, sample);

      *dst++ = (decoded & 0xFF);

      *dst++ = (decoded >> 8);

      sample = ((*src) >> 4);

      decoded = dsp_decode_ima_adpcm_sample(&context->adpcm, 0, sample);

      *dst++ = (decoded & 0xFF);

      *dst++ = (decoded >> 8);

      src++;

      size--;

    }

  }

  return TRUE;

}

#if defined(WITH_GSM)

static BOOL freerdp_dsp_decode_gsm610(FREERDP_DSP_CONTEXT* context, const BYTE* src, size_t size,

                                      wStream* out)

{

  size_t offset = 0;

  while (offset < size)

  {

    int rc;

    gsm_signal gsmBlockBuffer[160] = { 0 };

    rc = gsm_decode(context->gsm, (gsm_byte*)/* API does not modify */ &src[offset],

                    gsmBlockBuffer);

    if (rc < 0)

      return FALSE;

    if ((offset % 65) == 0)

      offset += 33;

    else

      offset += 32;

    if (!Stream_EnsureRemainingCapacity(out, sizeof(gsmBlockBuffer)))

      return FALSE;

    Stream_Write(out, (void*)gsmBlockBuffer, sizeof(gsmBlockBuffer));

  }

  return TRUE;

}

static BOOL freerdp_dsp_encode_gsm610(FREERDP_DSP_CONTEXT* context, const BYTE* src, size_t size,

                                      wStream* out)

{

  size_t offset = 0;

  while (offset < size)

  {

    const gsm_signal* signal = (const gsm_signal*)&src[offset];

    if (!Stream_EnsureRemainingCapacity(out, sizeof(gsm_frame)))

      return FALSE;

    gsm_encode(context->gsm, (gsm_signal*)/* API does not modify */ signal,

               Stream_Pointer(out));

    if ((offset % 65) == 0)

      Stream_Seek(out, 33);

    else

      Stream_Seek(out, 32);

    offset += 160;

  }

  return TRUE;

}

#endif

#if defined(WITH_LAME)

static BOOL freerdp_dsp_decode_mp3(FREERDP_DSP_CONTEXT* context, const BYTE* src, size_t size,

                                   wStream* out)

{

  int rc;

  short* pcm_l;

  short* pcm_r;

  size_t buffer_size;

  if (!context || !src || !out)

    return FALSE;

  buffer_size = 2 * context->format.nChannels * context->format.nSamplesPerSec;

  if (!Stream_EnsureCapacity(context->buffer, 2 * buffer_size))

    return FALSE;

  pcm_l = (short*)Stream_Buffer(context->buffer);

  pcm_r = (short*)Stream_Buffer(context->buffer) + buffer_size;

  rc = hip_decode(context->hip, (unsigned char*)/* API is not modifying content */ src, size,

                  pcm_l, pcm_r);

  if (rc <= 0)

    return FALSE;

  if (!Stream_EnsureRemainingCapacity(out, (size_t)rc * context->format.nChannels * 2))

    return FALSE;

  for (size_t x = 0; x < rc; x++)

  {

    Stream_Write_UINT16(out, (UINT16)pcm_l[x]);

    Stream_Write_UINT16(out, (UINT16)pcm_r[x]);

  }

  return TRUE;

}

static BOOL freerdp_dsp_encode_mp3(FREERDP_DSP_CONTEXT* context, const BYTE* src, size_t size,

                                   wStream* out)

{

  size_t samples_per_channel;

  int rc;

  if (!context || !src || !out)

    return FALSE;

  samples_per_channel = size / context->format.nChannels / context->format.wBitsPerSample / 8;

  /* Ensure worst case buffer size for mp3 stream taken from LAME header */

  if (!Stream_EnsureRemainingCapacity(out, 5 / 4 * samples_per_channel + 7200))

    return FALSE;

  samples_per_channel = size / 2 /* size of a sample */ / context->format.nChannels;

  rc = lame_encode_buffer_interleaved(context->lame, (short*)src, samples_per_channel,

                                      Stream_Pointer(out), Stream_GetRemainingCapacity(out));

  if (rc < 0)

    return FALSE;

  Stream_Seek(out, (size_t)rc);

  return TRUE;

}

#endif

#if defined(WITH_FAAC)

static BOOL freerdp_dsp_encode_faac(FREERDP_DSP_CONTEXT* context, const BYTE* src, size_t size,

                                    wStream* out)

{

  const int16_t* inSamples = (const int16_t*)src;

  unsigned int bpp;

  size_t nrSamples;

  int rc;

  if (!context || !src || !out)

    return FALSE;

  bpp = context->format.wBitsPerSample / 8;

  nrSamples = size / bpp;

  if (!Stream_EnsureRemainingCapacity(context->buffer, nrSamples * sizeof(int16_t)))

    return FALSE;

  for (size_t x = 0; x < nrSamples; x++)

  {

    Stream_Write_INT16(context->buffer, inSamples[x]);

    if (Stream_GetPosition(context->buffer) / bpp >= context->faacInputSamples)

    {

      if (!Stream_EnsureRemainingCapacity(out, context->faacMaxOutputBytes))

        return FALSE;

      rc = faacEncEncode(context->faac, (int32_t*)Stream_Buffer(context->buffer),

                         context->faacInputSamples, Stream_Pointer(out),

                         Stream_GetRemainingCapacity(out));

      if (rc < 0)

        return FALSE;

      if (rc > 0)

        Stream_Seek(out, (size_t)rc);

      Stream_SetPosition(context->buffer, 0);

    }

  }

  return TRUE;

}

#endif

#if defined(WITH_OPUS)

static BOOL freerdp_dsp_decode_opus(FREERDP_DSP_CONTEXT* context, const BYTE* src, size_t size,

                                    wStream* out)

{

  size_t max_size = 5760;

  int frames;

  if (!context || !src || !out)

    return FALSE;

  /* Max packet duration is 120ms (5760 at 48KHz) */

  max_size = OPUS_MAX_FRAMES * context->format.nChannels * sizeof(int16_t);

  if (!Stream_EnsureRemainingCapacity(context->buffer, max_size))

    return FALSE;

  frames = opus_decode(context->opus_decoder, src, size, Stream_Pointer(out), OPUS_MAX_FRAMES, 0);

  if (frames < 0)

    return FALSE;

  Stream_Seek(out, frames * context->format.nChannels * sizeof(int16_t));

  return TRUE;

}

static BOOL freerdp_dsp_encode_opus(FREERDP_DSP_CONTEXT* context, const BYTE* src, size_t size,

                                    wStream* out)

{

  if (!context || !src || !out)

    return FALSE;

  /* Max packet duration is 120ms (5760 at 48KHz) */

  const size_t max_size = OPUS_MAX_FRAMES * context->format.nChannels * sizeof(int16_t);

  if (!Stream_EnsureRemainingCapacity(context->buffer, max_size))

    return FALSE;

  const int src_frames = size / sizeof(opus_int16) / context->format.nChannels;

  const opus_int16* src_data = (const opus_int16*)src;

  const int frames =

      opus_encode(context->opus_encoder, src_data, src_frames, Stream_Pointer(out), max_size);

  if (frames < 0)

    return FALSE;

  return Stream_SafeSeek(out, frames * context->format.nChannels * sizeof(int16_t));

}

#endif

#if defined(WITH_FAAD2)

static BOOL freerdp_dsp_decode_faad(FREERDP_DSP_CONTEXT* context, const BYTE* src, size_t size,

                                    wStream* out)

{

  NeAACDecFrameInfo info;

  size_t offset = 0;

  if (!context || !src || !out)

    return FALSE;

  if (!context->faadSetup)

  {

    union

    {

      const void* cpv;

      void* pv;

    } cnv;

    unsigned long samplerate;

    unsigned char channels;

    long err;

    cnv.cpv = src;

    err = NeAACDecInit(context->faad, /* API is not modifying content */ cnv.pv, size,

                       &samplerate, &channels);

    if (err != 0)

      return FALSE;

    if (channels != context->format.nChannels)

      return FALSE;

    if (samplerate != context->format.nSamplesPerSec)

      return FALSE;

    context->faadSetup = TRUE;

  }

  while (offset < size)

  {

    union

    {

      const void* cpv;

      void* pv;

    } cnv;

    size_t outSize;

    void* sample_buffer;

    outSize = context->format.nSamplesPerSec * context->format.nChannels *

              context->format.wBitsPerSample / 8;

    if (!Stream_EnsureRemainingCapacity(out, outSize))

      return FALSE;

    sample_buffer = Stream_Pointer(out);

    cnv.cpv = &src[offset];

    NeAACDecDecode2(context->faad, &info, cnv.pv, size - offset, &sample_buffer,

                    Stream_GetRemainingCapacity(out));

    if (info.error != 0)

      return FALSE;

    offset += info.bytesconsumed;

    if (info.samples == 0)

      continue;

    Stream_Seek(out, info.samples * context->format.wBitsPerSample / 8);

  }

  return TRUE;

}

#endif

/**

 * 0     1     2     3

 * 2 0   6 4   10 8  14 12   <left>

 *

 * 4     5     6     7

 * 3 1   7 5   11 9  15 13   <right>

 */

static const struct

{

  BYTE byte_num;

  BYTE byte_shift;

} ima_stereo_encode_map[] = { { 0, 0 }, { 4, 0 }, { 0, 4 }, { 4, 4 }, { 1, 0 }, { 5, 0 },

                            { 1, 4 }, { 5, 4 }, { 2, 0 }, { 6, 0 }, { 2, 4 }, { 6, 4 },

                            { 3, 0 }, { 7, 0 }, { 3, 4 }, { 7, 4 } };

static BYTE dsp_encode_ima_adpcm_sample(ADPCM* adpcm, int channel, INT16 sample)

{

  INT32 e;

  INT32 d;

  INT32 ss;

  BYTE enc;

  INT32 diff;

  ss = ima_step_size_table[adpcm->ima.last_step[channel]];

  d = e = sample - adpcm->ima.last_sample[channel];

  diff = ss >> 3;

  enc = 0;

  if (e < 0)

  {

    enc = 8;

    e = -e;

  }

  if (e >= ss)

  {

    enc |= 4;

    e -= ss;

  }

  ss >>= 1;

  if (e >= ss)

  {

    enc |= 2;

    e -= ss;

  }

  ss >>= 1;

  if (e >= ss)

  {

    enc |= 1;

    e -= ss;

  }

  if (d < 0)

    diff = d + e - diff;

  else

    diff = d - e + diff;

  diff += adpcm->ima.last_sample[channel];

  if (diff < -32768)

    diff = -32768;

  else if (diff > 32767)

    diff = 32767;

  adpcm->ima.last_sample[channel] = (INT16)diff;

  adpcm->ima.last_step[channel] += ima_step_index_table[enc];

  if (adpcm->ima.last_step[channel] < 0)

    adpcm->ima.last_step[channel] = 0;

  else if (adpcm->ima.last_step[channel] > 88)

    adpcm->ima.last_step[channel] = 88;

  return enc;

}

static BOOL freerdp_dsp_encode_ima_adpcm(FREERDP_DSP_CONTEXT* context, const BYTE* src, size_t size,

                                         wStream* out)

{

  INT16 sample;

  BYTE encoded;

  size_t align;

  if (!Stream_EnsureRemainingCapacity(out, size))

    return FALSE;

  align = (context->format.nChannels > 1) ? 32 : 4;

  while (size >= align)

  {

    if (Stream_GetPosition(context->buffer) % context->format.nBlockAlign == 0)

    {

      Stream_Write_UINT8(context->buffer, context->adpcm.ima.last_sample[0] & 0xFF);

      Stream_Write_UINT8(context->buffer, (context->adpcm.ima.last_sample[0] >> 8) & 0xFF);

      Stream_Write_UINT8(context->buffer, (BYTE)context->adpcm.ima.last_step[0]);

      Stream_Write_UINT8(context->buffer, 0);

      if (context->format.nChannels > 1)

      {

        Stream_Write_UINT8(context->buffer, context->adpcm.ima.last_sample[1] & 0xFF);

        Stream_Write_UINT8(context->buffer,

                           (context->adpcm.ima.last_sample[1] >> 8) & 0xFF);

        Stream_Write_UINT8(context->buffer, (BYTE)context->adpcm.ima.last_step[1]);

        Stream_Write_UINT8(context->buffer, 0);

      }

    }

    if (context->format.nChannels > 1)

    {

      BYTE* dst = Stream_Pointer(context->buffer);

      ZeroMemory(dst, 8);

      for (size_t i = 0; i < 16; i++)

      {

        sample = (INT16)(((UINT16)(*src)) | (((UINT16)(*(src + 1))) << 8));

        src += 2;

        encoded = dsp_encode_ima_adpcm_sample(&context->adpcm, i % 2, sample);

        dst[ima_stereo_encode_map[i].byte_num] |= encoded

                                                  << ima_stereo_encode_map[i].byte_shift;

      }

      if (!Stream_SafeSeek(context->buffer, 8))

        return FALSE;

      size -= 32;

    }

    else

    {

      sample = (INT16)(((UINT16)(*src)) | (((UINT16)(*(src + 1))) << 8));

      src += 2;

      encoded = dsp_encode_ima_adpcm_sample(&context->adpcm, 0, sample);

      sample = (INT16)(((UINT16)(*src)) | (((UINT16)(*(src + 1))) << 8));

      src += 2;

      encoded |= dsp_encode_ima_adpcm_sample(&context->adpcm, 0, sample) << 4;

      Stream_Write_UINT8(context->buffer, encoded);

      size -= 4;

    }

    if (Stream_GetPosition(context->buffer) >= context->adpcm.ima.packet_size)

    {

      BYTE* bsrc = Stream_Buffer(context->buffer);

      Stream_Write(out, bsrc, context->adpcm.ima.packet_size);

      Stream_SetPosition(context->buffer, 0);

    }

  }

  return TRUE;

}

/**

 * Microsoft ADPCM Specification:

 *

 * http://wiki.multimedia.cx/index.php?title=Microsoft_ADPCM

 */

static const INT32 ms_adpcm_adaptation_table[] = { 230, 230, 230, 230, 307, 409, 512, 614,

                                                 768, 614, 512, 409, 307, 230, 230, 230 };

static const INT32 ms_adpcm_coeffs1[7] = { 256, 512, 0, 192, 240, 460, 392 };

static const INT32 ms_adpcm_coeffs2[7] = { 0, -256, 0, 64, 0, -208, -232 };

static INLINE INT16 freerdp_dsp_decode_ms_adpcm_sample(ADPCM* adpcm, BYTE sample, int channel)

{

  INT8 nibble;

  INT32 presample;

  nibble = (sample & 0x08 ? (INT8)sample - 16 : (INT8)sample);

  presample = ((adpcm->ms.sample1[channel] * ms_adpcm_coeffs1[adpcm->ms.predictor[channel]]) +

               (adpcm->ms.sample2[channel] * ms_adpcm_coeffs2[adpcm->ms.predictor[channel]])) /

              256;

  presample += nibble * adpcm->ms.delta[channel];

  if (presample > 32767)

    presample = 32767;

  else if (presample < -32768)

    presample = -32768;

  adpcm->ms.sample2[channel] = adpcm->ms.sample1[channel];

  adpcm->ms.sample1[channel] = presample;

  adpcm->ms.delta[channel] = adpcm->ms.delta[channel] * ms_adpcm_adaptation_table[sample] / 256;

  if (adpcm->ms.delta[channel] < 16)

    adpcm->ms.delta[channel] = 16;

  return (INT16)presample;

}

static BOOL freerdp_dsp_decode_ms_adpcm(FREERDP_DSP_CONTEXT* context, const BYTE* src, size_t size,

                                        wStream* out)

{

  BYTE sample;

  const size_t out_size = size * 4;

  const UINT32 channels = context->format.nChannels;

  const UINT32 block_size = context->format.nBlockAlign;

  if (!Stream_EnsureCapacity(out, out_size))

    return FALSE;

  while (size > 0)

  {

    if (size % block_size == 0)

    {

      if (channels > 1)

      {

        context->adpcm.ms.predictor[0] = *src++;

        context->adpcm.ms.predictor[1] = *src++;

        context->adpcm.ms.delta[0] = read_int16(src);

        src += 2;

        context->adpcm.ms.delta[1] = read_int16(src);

        src += 2;

        context->adpcm.ms.sample1[0] = read_int16(src);

        src += 2;

        context->adpcm.ms.sample1[1] = read_int16(src);

        src += 2;

        context->adpcm.ms.sample2[0] = read_int16(src);

        src += 2;

        context->adpcm.ms.sample2[1] = read_int16(src);

        src += 2;

        size -= 14;

        Stream_Write_INT16(out, (INT16)context->adpcm.ms.sample2[0]);

        Stream_Write_INT16(out, (INT16)context->adpcm.ms.sample2[1]);

        Stream_Write_INT16(out, (INT16)context->adpcm.ms.sample1[0]);

        Stream_Write_INT16(out, (INT16)context->adpcm.ms.sample1[1]);

      }

      else

      {

        context->adpcm.ms.predictor[0] = *src++;

        context->adpcm.ms.delta[0] = read_int16(src);

        src += 2;

        context->adpcm.ms.sample1[0] = read_int16(src);

        src += 2;

        context->adpcm.ms.sample2[0] = read_int16(src);

        src += 2;

        size -= 7;

        Stream_Write_INT16(out, (INT16)context->adpcm.ms.sample2[0]);

        Stream_Write_INT16(out, (INT16)context->adpcm.ms.sample1[0]);

      }

    }

    if (channels > 1)

    {

      sample = *src++;

      size--;

      Stream_Write_INT16(out,

                         freerdp_dsp_decode_ms_adpcm_sample(&context->adpcm, sample >> 4, 0));

      Stream_Write_INT16(

          out, freerdp_dsp_decode_ms_adpcm_sample(&context->adpcm, sample & 0x0F, 1));

      sample = *src++;

      size--;

      Stream_Write_INT16(out,

                         freerdp_dsp_decode_ms_adpcm_sample(&context->adpcm, sample >> 4, 0));

      Stream_Write_INT16(

          out, freerdp_dsp_decode_ms_adpcm_sample(&context->adpcm, sample & 0x0F, 1));

    }

    else

    {

      sample = *src++;

      size--;

      Stream_Write_INT16(out,

                         freerdp_dsp_decode_ms_adpcm_sample(&context->adpcm, sample >> 4, 0));

      Stream_Write_INT16(

          out, freerdp_dsp_decode_ms_adpcm_sample(&context->adpcm, sample & 0x0F, 0));

    }

  }

  return TRUE;

}