diff options
Diffstat (limited to 'arm-fm-22k/lib_src/eas_imaadpcm.c')
| -rw-r--r-- | arm-fm-22k/lib_src/eas_imaadpcm.c | 368 |
1 files changed, 368 insertions, 0 deletions
diff --git a/arm-fm-22k/lib_src/eas_imaadpcm.c b/arm-fm-22k/lib_src/eas_imaadpcm.c new file mode 100644 index 0000000..68bf257 --- /dev/null +++ b/arm-fm-22k/lib_src/eas_imaadpcm.c @@ -0,0 +1,368 @@ +/*----------------------------------------------------------------------------
+ *
+ * File:
+ * eas_imaadpcm.c
+ *
+ * Contents and purpose:
+ * Implements the IMA ADPCM decoder
+ *
+ * Copyright Sonic Network Inc. 2005
+ + * 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. + *
+ *----------------------------------------------------------------------------
+ * Revision Control:
+ * $Revision: 847 $
+ * $Date: 2007-08-27 21:30:08 -0700 (Mon, 27 Aug 2007) $
+ *----------------------------------------------------------------------------
+*/
+
+#include "eas_data.h"
+#include "eas_host.h"
+#include "eas_pcm.h"
+#include "eas_math.h"
+#include "eas_report.h"
+
+// #define _DEBUG_IMA_ADPCM_LOCATE
+
+/*----------------------------------------------------------------------------
+ * externs
+ *----------------------------------------------------------------------------
+*/
+extern const EAS_I16 imaIndexTable[];
+extern const EAS_I16 imaStepSizeTable[];
+
+/*----------------------------------------------------------------------------
+ * prototypes
+ *----------------------------------------------------------------------------
+*/
+static EAS_RESULT IMADecoderInit (EAS_DATA_HANDLE pEASData, S_PCM_STATE *pState);
+static EAS_RESULT IMADecoderSample (EAS_DATA_HANDLE pEASData, S_PCM_STATE *pState);
+static void IMADecoderADPCM (S_DECODER_STATE *pState, EAS_U8 nibble);
+static EAS_RESULT IMADecoderLocate (EAS_DATA_HANDLE pEASData, S_PCM_STATE *pState, EAS_I32 time);
+
+/*----------------------------------------------------------------------------
+ * IMA ADPCM Decoder interface
+ *----------------------------------------------------------------------------
+*/
+const S_DECODER_INTERFACE IMADecoder =
+{
+ IMADecoderInit,
+ IMADecoderSample,
+ IMADecoderLocate
+};
+
+/*----------------------------------------------------------------------------
+ * IMADecoderInit()
+ *----------------------------------------------------------------------------
+ * Purpose:
+ * Initializes the IMA ADPCM decoder
+ *
+ * Inputs:
+ *
+ *
+ * Outputs:
+ *
+ *
+ * Side Effects:
+ *
+ *----------------------------------------------------------------------------
+*/
+/*lint -esym(715, pEASData) common decoder interface - pEASData not used */
+static EAS_RESULT IMADecoderInit (EAS_DATA_HANDLE pEASData, S_PCM_STATE *pState)
+{
+ pState->decoderL.step = 0;
+ pState->decoderR.step = 0;
+ return EAS_SUCCESS;
+}
+
+/*----------------------------------------------------------------------------
+ * IMADecoderSample()
+ *----------------------------------------------------------------------------
+ * Purpose:
+ * Decodes an IMA ADPCM sample
+ *
+ * Inputs:
+ *
+ *
+ * Outputs:
+ *
+ *
+ * Side Effects:
+ *
+ *----------------------------------------------------------------------------
+*/
+static EAS_RESULT IMADecoderSample (EAS_DATA_HANDLE pEASData, S_PCM_STATE *pState)
+{
+ EAS_RESULT result;
+ EAS_I16 sTemp;
+
+ /* if high nibble, decode */
+ if (pState->hiNibble)
+ {
+ IMADecoderADPCM(&pState->decoderL, (EAS_U8)(pState->srcByte >> 4));
+ pState->hiNibble = EAS_FALSE;
+ }
+
+ /* low nibble, need to fetch another byte */
+ else
+ {
+ /* check for loop */
+ if ((pState->bytesLeft == 0) && (pState->loopSamples != 0))
+ {
+ /* seek to start of loop */
+ if ((result = EAS_HWFileSeek(pEASData->hwInstData, pState->fileHandle, (EAS_I32) (pState->startPos + pState->loopLocation))) != EAS_SUCCESS)
+ return result;
+ pState->bytesLeft = pState->byteCount = (EAS_I32) pState->bytesLeftLoop;
+ pState->blockCount = 0;
+ pState->flags &= ~PCM_FLAGS_EMPTY;
+ { /* dpp: EAS_ReportEx(_EAS_SEVERITY_DETAIL, "IMADecoderSample: Rewind file to %d, bytesLeft = %d\n", pState->startPos, pState->bytesLeft); */ }
+ }
+
+ /* if start of block, fetch new predictor and step index */
+ if ((pState->blockSize != 0) && (pState->blockCount == 0) && (pState->bytesLeft != 0))
+ {
+
+ /* get predicted sample for left channel */
+ if ((result = EAS_HWGetWord(pEASData->hwInstData, pState->fileHandle, &sTemp, EAS_FALSE)) != EAS_SUCCESS)
+ return result;
+#ifdef _DEBUG_IMA_ADPCM
+ { /* dpp: EAS_ReportEx(_EAS_SEVERITY_DETAIL, "Predictor: Was %d, now %d\n", pState->decoderL.acc, sTemp); */ }
+#endif
+ pState->decoderL.acc = pState->decoderL.x1 = sTemp;
+
+ /* get step index for left channel - upper 8 bits are reserved */
+ if ((result = EAS_HWGetWord(pEASData->hwInstData, pState->fileHandle, &sTemp, EAS_FALSE)) != EAS_SUCCESS)
+ return result;
+#ifdef _DEBUG_IMA_ADPCM
+ { /* dpp: EAS_ReportEx(_EAS_SEVERITY_DETAIL, "Step: Was %d, now %d\n", pState->decoderL.step, sTemp); */ }
+#endif
+ pState->decoderL.step = sTemp & 0xff;
+
+ if (pState->flags & PCM_FLAGS_STEREO)
+ {
+ /* get predicted sample for right channel */
+ if ((result = EAS_HWGetWord(pEASData->hwInstData, pState->fileHandle, &sTemp, EAS_FALSE)) != EAS_SUCCESS)
+ return result;
+ pState->decoderR.acc = pState->decoderR.x1 = sTemp;
+
+ /* get step index for right channel - upper 8 bits are reserved */
+ if ((result = EAS_HWGetWord(pEASData->hwInstData, pState->fileHandle, &sTemp, EAS_FALSE)) != EAS_SUCCESS)
+ return result;
+#ifdef _DEBUG_IMA_ADPCM
+ { /* dpp: EAS_ReportEx(_EAS_SEVERITY_DETAIL, "Step: Was %d, now %d\n", pState->decoderR.step, sTemp); */ }
+#endif
+ pState->decoderR.step = sTemp & 0xff;
+
+ pState->blockCount = pState->blockSize - 8;
+ pState->bytesLeft -= 8;
+ }
+ else
+ {
+ pState->blockCount = pState->blockSize - 4;
+ pState->bytesLeft -= 4;
+ }
+ }
+ else
+ {
+
+ /* get another ADPCM data pair */
+ if (pState->bytesLeft)
+ {
+
+ if ((result = EAS_HWGetByte(pEASData->hwInstData, pState->fileHandle, &pState->srcByte)) != EAS_SUCCESS)
+ return result;
+
+ /* decode the low nibble */
+ pState->bytesLeft--;
+ pState->blockCount--;
+ IMADecoderADPCM(&pState->decoderL, (EAS_U8)(pState->srcByte & 0x0f));
+
+ if (pState->flags & PCM_FLAGS_STEREO)
+ IMADecoderADPCM(&pState->decoderR, (EAS_U8)(pState->srcByte >> 4));
+ else
+ pState->hiNibble = EAS_TRUE;
+ }
+
+ /* out of ADPCM data, generate enough samples to fill buffer */
+ else
+ {
+ pState->decoderL.x1 = pState->decoderL.x0;
+ pState->decoderR.x1 = pState->decoderR.x0;
+ }
+ }
+ }
+
+ return EAS_SUCCESS;
+}
+
+/*----------------------------------------------------------------------------
+ * IMADecoderADPCM()
+ *----------------------------------------------------------------------------
+ * Purpose:
+ * Decodes an IMA ADPCM sample
+ *
+ * Inputs:
+ *
+ *
+ * Outputs:
+ *
+ *
+ * Side Effects:
+ *
+ *----------------------------------------------------------------------------
+*/
+static void IMADecoderADPCM (S_DECODER_STATE *pState, EAS_U8 nibble)
+{
+ EAS_INT delta;
+ EAS_INT stepSize;
+
+ /* get stepsize from table */
+ stepSize = imaStepSizeTable[pState->step];
+
+ /* delta = (abs(delta) + 0.5) * step / 4 */
+ delta = 0;
+ if (nibble & 4)
+ delta += stepSize;
+
+ if (nibble & 2)
+ /*lint -e{702} use shift for performance */
+ delta += stepSize >> 1;
+
+ if (nibble & 1)
+ /*lint -e{702} use shift for performance */
+ delta += stepSize >> 2;
+
+ /*lint -e{702} use shift for performance */
+ delta += stepSize >> 3;
+
+ /* integrate the delta */
+ if (nibble & 8)
+ pState->acc -= delta;
+ else
+ pState->acc += delta;
+
+ /* saturate */
+ if (pState->acc > 32767)
+ pState->acc = 32767;
+ if (pState->acc < -32768)
+ pState->acc = -32768;
+ pState->x1 = (EAS_PCM) pState->acc;
+
+ /* compute new step size */
+ pState->step += imaIndexTable[nibble];
+ if (pState->step < 0)
+ pState->step = 0;
+ if (pState->step > 88)
+ pState->step = 88;
+
+#ifdef _DEBUG_IMA_ADPCM
+ { /* dpp: EAS_ReportEx(_EAS_SEVERITY_DETAIL, "In=%u, Pred=%d, Step=%d\n", nibble, pState->acc, imaStepSizeTable[pState->step]); */ }
+#endif
+}
+
+/*----------------------------------------------------------------------------
+ * IMADecoderLocate()
+ *----------------------------------------------------------------------------
+ * Locate in an IMA ADPCM stream
+ *----------------------------------------------------------------------------
+*/
+static EAS_RESULT IMADecoderLocate (EAS_DATA_HANDLE pEASData, S_PCM_STATE *pState, EAS_I32 time)
+{
+ EAS_RESULT result;
+ EAS_I32 temp;
+ EAS_I32 samplesPerBlock;
+ EAS_I32 secs, msecs;
+
+ /* no need to calculate if time is zero */
+ if (time == 0)
+ temp = 0;
+
+ /* not zero */
+ else
+ {
+
+ /* can't seek if not a blocked file */
+ if (pState->blockSize == 0)
+ return EAS_ERROR_FEATURE_NOT_AVAILABLE;
+
+ /* calculate number of samples per block */
+ if (pState->flags & PCM_FLAGS_STEREO)
+ samplesPerBlock = pState->blockSize - 7;
+ else
+ samplesPerBlock = (pState->blockSize << 1) - 7;
+
+ /* break down into secs and msecs */
+ secs = time / 1000;
+ msecs = time - (secs * 1000);
+
+ /* calculate sample number fraction from msecs */
+ temp = (msecs * pState->sampleRate);
+ temp = (temp >> 10) + ((temp * 49) >> 21);
+
+ /* add integer sample count */
+ temp += secs * pState->sampleRate;
+
+#ifdef _DEBUG_IMA_ADPCM_LOCATE
+ EAS_ReportEx(_EAS_SEVERITY_NOFILTER, 0x2380b977, 0x00000006 , time, temp);
+#endif
+
+ /* for looped samples, calculate position in the loop */
+ if ((temp > pState->byteCount) && (pState->loopSamples != 0))
+ {
+ EAS_I32 numBlocks;
+ EAS_I32 samplesPerLoop;
+ EAS_I32 samplesInLastBlock;
+
+ numBlocks = (EAS_I32) (pState->loopStart / pState->blockSize);
+ samplesInLastBlock = (EAS_I32) pState->loopStart - (numBlocks * pState->blockSize);
+ if (samplesInLastBlock)
+ {
+ if (pState->flags & PCM_FLAGS_STEREO)
+ samplesInLastBlock = samplesInLastBlock - 7;
+ else
+ /*lint -e{703} use shift for performance */
+ samplesInLastBlock = (samplesInLastBlock << 1) - 7;
+ }
+ samplesPerLoop = numBlocks * samplesPerBlock + samplesInLastBlock;
+ temp = temp % samplesPerLoop;
+#ifdef _DEBUG_IMA_ADPCM_LOCATE
+ EAS_ReportEx(_EAS_SEVERITY_NOFILTER, 0x2380b977, 0x00000007 , numBlocks, samplesPerLoop, samplesInLastBlock, temp);
+#endif
+ }
+
+ /* find start of block for requested sample */
+ temp = (temp / samplesPerBlock) * pState->blockSize;
+#ifdef _DEBUG_IMA_ADPCM_LOCATE
+ EAS_ReportEx(_EAS_SEVERITY_NOFILTER, 0x2380b977, 0x00000008 , temp);
+#endif
+
+ }
+
+ /* seek to new location */
+ if ((result = EAS_PESeek(pEASData, pState, &temp)) != EAS_SUCCESS)
+ return result;
+
+#ifdef _DEBUG_IMA_ADPCM_LOCATE
+ EAS_ReportEx(_EAS_SEVERITY_NOFILTER, 0x2380b977, 0x00000009 , pState->bytesLeft);
+#endif
+
+ /* reset state */
+ pState->blockCount = 0;
+ pState->hiNibble = EAS_FALSE;
+ if ((pState->state != EAS_STATE_PAUSING) && (pState->state != EAS_STATE_PAUSED))
+ pState->state = EAS_STATE_READY;
+
+ return EAS_SUCCESS;
+}
+
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