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Topic: vorbis decoder probems on VIA C3 processor (Read 2775 times) previous topic - next topic
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vorbis decoder probems on VIA C3 processor

hi there.
i have extracted all the vorbis packets and get it in the array. Then,
i try to decompress data and convert it to pcm. all works fine with
Visual Studio 2003, but when i compile vorbis and my code in WindowsCE
Platform Builder under x86 VIA processor (mini-ITX MB Epia-SP) i hear
slight gaps, "speed-downs" and "speed-ups". Can anybody tell me, why?



i have such code:
Code: [Select]
       //init
        vorbis_synthesis_init(&vorb_dsp_state,&m_vorb_info);
        vorbis_block_init(&vorb_dsp_state,&vorb_block);   

        offset = 0;
        // go through

        for (uint32 p = 3; p < m_packets_number; p++)
        {
                float ** pcm = NULL;
                int samples;
                if (vorbis_synthesis(&vorb_block,&m_packets[p],1)==0) 
                        vorbis_synthesis_blockin(&vorb_dsp_state,&vorb_block);

                        // using no more than 4096
                while ( (samples = vorbis_synthesis_pcmout(&vorb_dsp_state, &pcm)) > 0) 
                {
                        int bout=(samples<4096) ? samples : 4096;
                        float * pcm_fr[2];
                        for (i = 0; i < (uint32)m_vorb_info.channels; i++)
                                pcm_fr[i] = pcm[i];

                                //my own func, see below
                        ConvertOGGToPCM(reinterpret_cast<int16 *>(m_fake_data) + offset, pcm_fr, bout, m_vorb_info.channels);
                        offset += bout * m_vorb_info.channels;

                        vorbis_synthesis_read(&vorb_dsp_state,bout);
                }
        }

        vorbis_block_clear(&vorb_block);
        vorbis_dsp_clear(&vorb_dsp_state);

        
void ConvertOGGToPCM(int16 * dst, const float * const * src, uint32 sample_cnt, uint32 channels )
{
        for (uint32 i = 0; i < channels; i++)
        {
                int16 *ptr = dst+i;
                const float *mono = src[i];
                for (uint32 j = 0; j < sample_cnt; j++)
                {
                        int val = int(mono[j] * 32767.f);
                        if(val > 32767)
                                val = 32767;
                        if(val < -32768)
                                val =- 32768;
                        *ptr = val;
                        ptr += channels;
                }
        }
}