alacenc: implement the 2-pass prediction type.
This isn't used by the reference encoder, but it is supported by the decoder.
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@ -348,6 +348,7 @@ static void alac_entropy_coder(AlacEncodeContext *s)
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static void write_compressed_frame(AlacEncodeContext *s)
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static void write_compressed_frame(AlacEncodeContext *s)
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{
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{
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int i, j;
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int i, j;
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int prediction_type = 0;
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if (s->avctx->channels == 2)
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if (s->avctx->channels == 2)
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alac_stereo_decorrelation(s);
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alac_stereo_decorrelation(s);
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@ -358,7 +359,7 @@ static void write_compressed_frame(AlacEncodeContext *s)
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calc_predictor_params(s, i);
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calc_predictor_params(s, i);
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put_bits(&s->pbctx, 4, 0); // prediction type : currently only type 0 has been RE'd
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put_bits(&s->pbctx, 4, prediction_type);
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put_bits(&s->pbctx, 4, s->lpc[i].lpc_quant);
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put_bits(&s->pbctx, 4, s->lpc[i].lpc_quant);
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put_bits(&s->pbctx, 3, s->rc.rice_modifier);
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put_bits(&s->pbctx, 3, s->rc.rice_modifier);
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@ -373,6 +374,14 @@ static void write_compressed_frame(AlacEncodeContext *s)
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for (i = 0; i < s->avctx->channels; i++) {
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for (i = 0; i < s->avctx->channels; i++) {
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alac_linear_predictor(s, i);
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alac_linear_predictor(s, i);
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// TODO: determine when this will actually help. for now it's not used.
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if (prediction_type == 15) {
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// 2nd pass 1st order filter
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for (j = s->avctx->frame_size - 1; j > 0; j--)
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s->predictor_buf[j] -= s->predictor_buf[j - 1];
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}
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alac_entropy_coder(s);
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alac_entropy_coder(s);
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}
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}
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}
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}
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