mp3einit.c

Intel提供的在Sitsang等嵌入式开发平台上使用Linux操作系统

/******************************************************************************
//               INTEL CORPORATION PROPRIETARY INFORMATION
//  This software is supplied under the terms of a license agreement or
//  nondisclosure agreement with Intel Corporation and may not be copied
//  or disclosed except in accordance with the terms of that agreement.
//        Copyright (C) 2003 Intel Corporation. All Rights Reserved.
//
//  Description:
//    Intel(R) Integrated Performance Primitives Sample Code MP3 Encoder
// 
//  Function List:
//    encoder_init_alloc_mp3()
//    encoder_free_mp3()
******************************************************************************/
#include "sampmp3.h"
/******************************************************************************
// Name:			 encoder_init_alloc_mp3
// Description:		 Initialize for MP3 encoder.
// Input Arguments : enc_state  - pointer to encoder state structure.
// Output Arguments: sound      - pointer to sound structure.
//					 stream_buf - pointer to stream structure.
//					 enc_state  - pointer to updated encoder state structure.
// Returns:			 
//          SAMPLE_STATUS_BADARG_ERR    - Bad argument
//          SAMPLE_STATUS_NOERR         - Initialize successfully
******************************************************************************/
sample_status encoder_init_alloc_mp3(sample_sound *sound, 
                                     sample_bitstream *stream_buf, 
                                     mp3_enc_state *enc_state)
{
	
	int headsideInfo_length;
	int bit_rate;
    int sampling_freq;
	IppMP3FrameHeader *frame_header;
	IppMP3EncPsychoAcousticModel2State *psy_state;
	IppMP3PsychoacousticModelTwoAnalysis *psy_info;
    int i,j,k;
    int buf_size;
    int align;
    /* Bad argument check */
	if(!(sound && stream_buf && enc_state)) {
		return SAMPLE_STATUS_BADARG_ERR;
	}

    /* Allocate buffer for input PCM */
    buf_size = (enc_state->channel_num == 1)?2304: 4608;
    align = 2;
    if (alloc_align_mem_mp3((void*)&sound->snd_frame, buf_size, align)
        != SAMPLE_STATUS_NOERR) {
        return SAMPLE_STATUS_NOMEM_ERR;
    }
    /* Initialize sound structure */
	sound->snd_len = (enc_state->channel_num == 1)?2304:4608;
	sound->snd_channel_num = enc_state->channel_num;
	sound->snd_sample_rate = mpeg1_samplerate_table[enc_state->sample_rate];

    /* Allocate buffer for input PCM */
    buf_size = 1024*8 + 1;
    align = 1;
    if (alloc_align_mem_mp3((void*)&stream_buf->bs_buffer, buf_size, align)
        != SAMPLE_STATUS_NOERR) {
        return SAMPLE_STATUS_NOMEM_ERR;
    }
    /* Initialize output bit stream structure */
	stream_buf->bs_bytelen = MP3_STREAMBUF_SIZE;
	stream_buf->bs_cur_byte = stream_buf->bs_buffer;
	stream_buf->bs_cur_bitoffset = 0;

	/* Initialize encode state structure */
	headsideInfo_length = 4 + ((enc_state->channel_num == 2)?32:17);
	enc_state->hdsi_len = headsideInfo_length;
	enc_state->bytes_per_frame = mpeg1_slot_table[enc_state->sample_rate]\
        [enc_state->bitrate_index];
	enc_state->bits_per_frame = ((enc_state->bytes_per_frame) <<3);
	enc_state->meanbits_num = enc_state->bits_per_frame - ((enc_state->hdsi_len)<<3);

    /* enc_state->frame_byte_dif is used to detemine whether 
    //or not to use padding */
	bit_rate = mpeg1_bitrate_table[enc_state->bitrate_index];
	sampling_freq = mpeg1_samplerate_table[enc_state->sample_rate];
	enc_state->frame_byte_dif = 144 * bit_rate - \
        ( enc_state->bytes_per_frame) * sampling_freq;

    /* Initialize the header and side info buffer */
	enc_state->hdsi_buf_ptr = enc_state->hdsi_buf;
	for(i=0; i<MP3_HEADERSIDEINFOBUF_SIZE; i++) {
		enc_state->hdsi_buf_ptr[i] = 0;
	}
    /* Initialize the main data buffer */
	enc_state->cur_maindata_buf = enc_state->maindata_buf;
	for(i=0; i<MP3_MAINDATABUF_SIZE; i++) {
		enc_state->cur_maindata_buf[i] = 0;
	}
    /* Initialize the scalefactor buffer */
	for(i = 0; i < IPP_MP3_SF_BUF_LEN*MP3_MAXGRANNULE_NUM*MP3_MAXCHANNEL_NUM; i ++) {
		enc_state->scale_factor[i] = 0;
	}
    /* Initialize the scalefactor selection info */
	for(i = 0; i < MP3_SCFBANDGROUP_NUM*IPP_MP3_CHANNEL_NUM; i ++) {
		enc_state->scfsi[i] = 0;
	}
	for(i=0; i<6; i++) {
		enc_state->is_sfb_bound[i] = 0;
	}
	for(i = 0; i < MP3_FRAME_LEN; i ++) {
		enc_state->overlap_buf[i] = 0;
	}
    /* Initialize the input PCM buffer */
 	for(i = 0; i < MP3_INPUTPCMBUF_SIZE; i ++) {
		enc_state->pcm_state_buf[i] = 0;
	}
	buffer_set_audio(0, enc_state->work_buf, MP3_WORKBUF_SIZE);
	
	enc_state->rest = 0;

	/*Initialize the psycho-acoustic model status */
	for(i = 0; i < MP3_MAXGRANPERFRAME_NUM; i ++) {
		psy_state = &(enc_state->psy_state[i]);
		for(j = 0; j < 2; j ++) {
			for(k = 0; k < IPP_MP3_PSY_BAND_LONG_NUM; k ++) {
				psy_state->pPrevMaskedThresholdLong[j][k] = (Ipp64s)0;
			}

			for(k = 0; k < FIRST_6_CW; k ++) {
				psy_state->pPrevFFT[j][k].re = 0;
				psy_state->pPrevFFT[j][k].im = 0;
				psy_state->pPrevFFTMag[j][k] = 0;
			}
		}

		for(j = 0; j < IPP_MP3_PSY_BAND_SHORT_NUM; j ++) {
			psy_state->pPrevMaskedThresholdShort[j] = 0;
		}
		psy_state->nextPerceptualEntropy = 0;
		psy_state->nextBlockType = 0;
		for(j = 0; j < IPP_MP3_SF_BUF_LEN; j ++) {
			psy_state->pNextMSRLong[j] = 0;
			psy_state->pNextMSRShort[j] = 0;
		}
	}
	/* Initialize the psycho-acoustic model output info */
	for(i=0;i<MP3_MAXGRANPERFRAME_NUM;i++) {
		psy_info = &(enc_state->psy_info[i]);
		for(j=0; j< 36; j++) {
			psy_info->pPsyMSR[j] = 0;
		}
		psy_info->PE = 0;
	}

	/* Initialize the output buffer control information */
	buffer_set_audio(0, &(enc_state->bufferedframe_num), 1);
	buffer_set_audio(0, &(enc_state->bufferedframe_index),1);
	buffer_set_audio(0, enc_state->mdframe_buf_len, MP3_MAXBUFFEREDFRAME_NUM);
	buffer_set_audio(0, enc_state->frame_len, MP3_MAXBUFFEREDFRAME_NUM);
	for(i =0; i<MP3_MAXBUFFEREDFRAME_NUM; i++) {
		enc_state->mdframe_buf_ptr[i] = NULL;	
	}

	/* Initialize frame header */
	frame_header = &enc_state->frame_header;
	frame_header->samplingFreq = enc_state->sample_rate;
	frame_header->bitRate = enc_state->bitrate_index;
	frame_header->id = 1;
	if(enc_state->channel_num == 2) {
		frame_header->mode = 1;		
		frame_header->modeExt = 2;	
	} else {
		frame_header->mode = 3;
		frame_header->modeExt = 0;
	}
	frame_header->layer = 1;
	frame_header->protectionBit = 1;
	frame_header->paddingBit = 1;
	frame_header->privateBit = 0;
	frame_header->copyright = 0;
	frame_header->originalCopy = 0;
	frame_header->emphasis = 0;
	frame_header->CRCWord = 0;

	/* Intialize the bit reservoir */
	ippsBitReservoirInit_MP3(&(enc_state->bit_resv), frame_header);

	return SAMPLE_STATUS_NOERR;
} 

sample_status encoder_free_mp3(sample_sound *sound,
                                 sample_bitstream *stream_buf)
{
    /* Free buffer for input PCM */
    free_align_mem_mp3((void*)&sound->snd_frame);
    /* Free buffer for output bit stream */
    free_align_mem_mp3((void*)&stream_buf->bs_buffer);
    return SAMPLE_STATUS_NOERR;
}