Clarify comment: although still hacky, it is correct for existing libtheora

[ffmpeg] / libavcodec / alacenc.c

diff --git a/libavcodec/alacenc.c b/libavcodec/alacenc.c
index df4136f4c40df2f1431606b072c6a3716bdac4ba..70b3b0f2b102fdb952603e1b5d046d376685ee73 100644 (file)
--- a/libavcodec/alacenc.c
+++ b/libavcodec/alacenc.c
@@ -20,9 +20,11 @@
  */
 
 #include "avcodec.h"
-#include "bitstream.h"
+#include "get_bits.h"
+#include "put_bits.h"
 #include "dsputil.h"
 #include "lpc.h"
+#include "mathops.h"
 
 #define DEFAULT_FRAME_SIZE        4096
 #define DEFAULT_SAMPLE_SIZE       16
@@ -121,7 +123,7 @@ static void write_frame_header(AlacEncodeContext *s, int is_verbatim)
     put_bits(&s->pbctx, 1,  1);                             // Sample count is in the header
     put_bits(&s->pbctx, 2,  0);                             // FIXME: Wasted bytes field
     put_bits(&s->pbctx, 1,  is_verbatim);                   // Audio block is verbatim
-    put_bits(&s->pbctx, 32, s->avctx->frame_size);          // No. of samples in the frame
+    put_bits32(&s->pbctx, s->avctx->frame_size);            // No. of samples in the frame
 }
 
 static void calc_predictor_params(AlacEncodeContext *s, int ch)
@@ -130,12 +132,27 @@ static void calc_predictor_params(AlacEncodeContext *s, int ch)
     int shift[MAX_LPC_ORDER];
     int opt_order;
 
-    opt_order = ff_lpc_calc_coefs(&s->dspctx, s->sample_buf[ch], s->avctx->frame_size, s->min_prediction_order, s->max_prediction_order,
-                                   ALAC_MAX_LPC_PRECISION, coefs, shift, 1, ORDER_METHOD_EST, ALAC_MAX_LPC_SHIFT, 1);
-
-    s->lpc[ch].lpc_order = opt_order;
-    s->lpc[ch].lpc_quant = shift[opt_order-1];
-    memcpy(s->lpc[ch].lpc_coeff, coefs[opt_order-1], opt_order*sizeof(int));
+    if (s->compression_level == 1) {
+        s->lpc[ch].lpc_order = 6;
+        s->lpc[ch].lpc_quant = 6;
+        s->lpc[ch].lpc_coeff[0] =  160;
+        s->lpc[ch].lpc_coeff[1] = -190;
+        s->lpc[ch].lpc_coeff[2] =  170;
+        s->lpc[ch].lpc_coeff[3] = -130;
+        s->lpc[ch].lpc_coeff[4] =   80;
+        s->lpc[ch].lpc_coeff[5] =  -25;
+    } else {
+        opt_order = ff_lpc_calc_coefs(&s->dspctx, s->sample_buf[ch],
+                                      s->avctx->frame_size,
+                                      s->min_prediction_order,
+                                      s->max_prediction_order,
+                                      ALAC_MAX_LPC_PRECISION, coefs, shift, 1,
+                                      ORDER_METHOD_EST, ALAC_MAX_LPC_SHIFT, 1);
+
+        s->lpc[ch].lpc_order = opt_order;
+        s->lpc[ch].lpc_quant = shift[opt_order-1];
+        memcpy(s->lpc[ch].lpc_coeff, coefs[opt_order-1], opt_order*sizeof(int));
+    }
 }
 
 static int estimate_stereo_mode(int32_t *left_ch, int32_t *right_ch, int n)
@@ -253,7 +270,8 @@ static void alac_linear_predictor(AlacEncodeContext *s, int ch)
 
             sum >>= lpc.lpc_quant;
             sum += samples[0];
-            residual[i] = samples[lpc.lpc_order+1] - sum;
+            residual[i] = sign_extend(samples[lpc.lpc_order+1] - sum,
+                                      s->write_sample_size);
             res_val = residual[i];
 
             if(res_val) {
@@ -329,7 +347,6 @@ static void write_compressed_frame(AlacEncodeContext *s)
 {
     int i, j;
 
-    /* only simple mid/side decorrelation supported as of now */
     if(s->avctx->channels == 2)
         alac_stereo_decorrelation(s);
     put_bits(&s->pbctx, 8, s->interlacing_shift);
@@ -373,9 +390,9 @@ static av_cold int alac_encode_init(AVCodecContext *avctx)
 
     // Set default compression level
     if(avctx->compression_level == FF_COMPRESSION_DEFAULT)
-        s->compression_level = 1;
+        s->compression_level = 2;
     else
-        s->compression_level = av_clip(avctx->compression_level, 0, 1);
+        s->compression_level = av_clip(avctx->compression_level, 0, 2);
 
     // Initialize default Rice parameters
     s->rc.history_mult    = 40;
@@ -383,8 +400,7 @@ static av_cold int alac_encode_init(AVCodecContext *avctx)
     s->rc.k_modifier      = 14;
     s->rc.rice_modifier   = 4;
 
-    s->max_coded_frame_size = (ALAC_FRAME_HEADER_SIZE + ALAC_FRAME_FOOTER_SIZE +
-                               avctx->frame_size*avctx->channels*avctx->bits_per_coded_sample)>>3;
+    s->max_coded_frame_size = 8 + (avctx->frame_size*avctx->channels*avctx->bits_per_coded_sample>>3);
 
     s->write_sample_size  = avctx->bits_per_coded_sample + avctx->channels - 1; // FIXME: consider wasted_bytes