From 82595311602a327dc52aef96e0ed151b4ae5046b Mon Sep 17 00:00:00 2001
From: Gregory Maxwell <greg@xiph.org>
Date: Tue, 30 Sep 2008 18:20:14 -0400
Subject: [PATCH] API: Change celt_encode and celt_encode_float so that they
 take an optional synthesis parameter after the PCM input. If
 optional_synthesis is null the encoder will be able to save some computation.
 If optional_synthesis is non-null if will be used to write the encoder's
 expectation of the decoder's output. Synthesis may alias the input pcm, so
 calling the encoder with the same buffer twice will achieve the old behavior.
 Remove 'restrict' from the CTL prototype.

---
 libcelt/celt.c     | 53 +++++++++++++++++++++++++---------------------
 libcelt/celt.h     |  6 +++---
 libcelt/testcelt.c |  2 +-
 tools/celtclient.c |  4 ++--
 tools/celtenc.c    |  2 +-
 5 files changed, 36 insertions(+), 31 deletions(-)

diff --git a/libcelt/celt.c b/libcelt/celt.c
index d582438c..002fd083 100644
--- a/libcelt/celt.c
+++ b/libcelt/celt.c
@@ -371,10 +371,10 @@ static void compute_inv_mdcts(const CELTMode *mode, int shortBlocks, celt_sig_t
 }
 
 #ifdef FIXED_POINT
-int celt_encode(CELTEncoder * restrict st, celt_int16_t * restrict pcm, unsigned char *compressed, int nbCompressedBytes)
+int celt_encode(CELTEncoder * restrict st, const celt_int16_t * pcm, celt_int16_t * optional_synthesis, unsigned char *compressed, int nbCompressedBytes)
 {
 #else
-int celt_encode_float(CELTEncoder * restrict st, celt_sig_t * restrict pcm, unsigned char *compressed, int nbCompressedBytes)
+int celt_encode_float(CELTEncoder * restrict st, const celt_sig_t * pcm, celt_sig_t * optional_synthesis, unsigned char *compressed, int nbCompressedBytes)
 {
 #endif
    int i, c, N, N4;
@@ -602,7 +602,7 @@ int celt_encode_float(CELTEncoder * restrict st, celt_sig_t * restrict pcm, unsi
    /* Residual quantisation */
    quant_bands(st->mode, X, P, NULL, bandE, stereo_mode, pulses, shortBlocks, nbCompressedBytes*8, &st->enc);
    
-   if (st->pitch_enabled)
+   if (st->pitch_enabled || optional_synthesis!=NULL)
    {
       if (C==2)
          renormalise_bands(st->mode, X);
@@ -614,19 +614,19 @@ int celt_encode_float(CELTEncoder * restrict st, celt_sig_t * restrict pcm, unsi
       
       compute_inv_mdcts(st->mode, shortBlocks, freq, transient_time, transient_shift, st->out_mem);
       /* De-emphasis and put everything back at the right place in the synthesis history */
-#ifndef SHORTCUTS
-      for (c=0;c<C;c++)
-      {
-         int j;
-         for (j=0;j<N;j++)
+      if (optional_synthesis != NULL) {
+         for (c=0;c<C;c++)
          {
-            celt_sig_t tmp = MAC16_32_Q15(st->out_mem[C*(MAX_PERIOD-N)+C*j+c],
+            int j;
+            for (j=0;j<N;j++)
+            {
+               celt_sig_t tmp = MAC16_32_Q15(st->out_mem[C*(MAX_PERIOD-N)+C*j+c],
                                    preemph,st->preemph_memD[c]);
-            st->preemph_memD[c] = tmp;
-            pcm[C*j+c] = SCALEOUT(SIG2WORD16(tmp));
+               st->preemph_memD[c] = tmp;
+               optional_synthesis[C*j+c] = SCALEOUT(SIG2WORD16(tmp));
+            }
          }
       }
-#endif
    }
    /*fprintf (stderr, "remaining bits after encode = %d\n", nbCompressedBytes*8-ec_enc_tell(&st->enc, 0));*/
    /*if (ec_enc_tell(&st->enc, 0) < nbCompressedBytes*8 - 7)
@@ -668,7 +668,7 @@ int celt_encode_float(CELTEncoder * restrict st, celt_sig_t * restrict pcm, unsi
 
 #ifdef FIXED_POINT
 #ifndef DISABLE_FLOAT_API
-int celt_encode_float(CELTEncoder * restrict st, float * restrict pcm, unsigned char *compressed, int nbCompressedBytes)
+int celt_encode_float(CELTEncoder * restrict st, const float * pcm, float * optional_synthesis, unsigned char *compressed, int nbCompressedBytes)
 {
    int j, ret;
    const int C = CHANNELS(st->mode);
@@ -679,18 +679,20 @@ int celt_encode_float(CELTEncoder * restrict st, float * restrict pcm, unsigned
    for (j=0;j<C*N;j++)
      in[j] = FLOAT2INT16(pcm[j]);
 
-   ret=celt_encode(st,in,compressed,nbCompressedBytes);
-#ifndef SHORTCUTS
+   if (optional_synthesis != NULL) {
+     ret=celt_encode(st,in,in,compressed,nbCompressedBytes);
    /*Converts backwards for inplace operation*/
-   for (j=0;j=C*N;j++)
-     pcm[j]=in[j]*(1/32768.);
-#endif
+      for (j=0;j=C*N;j++)
+         optional_synthesis[j]=in[j]*(1/32768.);
+   } else {
+     ret=celt_encode(st,in,NULL,compressed,nbCompressedBytes);
+   }
    return ret;
 
 }
 #endif /*DISABLE_FLOAT_API*/
 #else
-int celt_encode(CELTEncoder * restrict st, celt_int16_t * restrict pcm, unsigned char *compressed, int nbCompressedBytes)
+int celt_encode(CELTEncoder * restrict st, const celt_int16_t * pcm, celt_int16_t * optional_synthesis, unsigned char *compressed, int nbCompressedBytes)
 {
    int j, ret;
    VARDECL(celt_sig_t, in);
@@ -701,12 +703,15 @@ int celt_encode(CELTEncoder * restrict st, celt_int16_t * restrict pcm, unsigned
    for (j=0;j<C*N;j++) {
      in[j] = SCALEOUT(pcm[j]);
    }
-   ret = celt_encode_float(st,in,compressed,nbCompressedBytes);
-#ifndef SHORTCUTS
-   for (j=0;j<C*N;j++)
-     pcm[j] = FLOAT2INT16(in[j]);
 
-#endif
+   if (optional_synthesis != NULL) {
+      ret = celt_encode_float(st,in,in,compressed,nbCompressedBytes);
+      for (j=0;j<C*N;j++)
+         optional_synthesis[j] = FLOAT2INT16(in[j]);
+   } else {
+      ret = celt_encode_float(st,in,NULL,compressed,nbCompressedBytes);
+   }
+
    return ret;
 }
 #endif
diff --git a/libcelt/celt.h b/libcelt/celt.h
index 32d6a6f1..92f54794 100644
--- a/libcelt/celt.h
+++ b/libcelt/celt.h
@@ -152,8 +152,8 @@ EXPORT void celt_encoder_destroy(CELTEncoder *st);
          has occured (see error codes). It is IMPORTANT that the length returned
          be somehow transmitted to the decoder. Otherwise, no decoding is possible.
 */
-EXPORT int celt_encode_float(CELTEncoder *st, float *pcm, unsigned char *compressed, int nbCompressedBytes);
-EXPORT int celt_encode(CELTEncoder *st, celt_int16_t *pcm, unsigned char *compressed, int nbCompressedBytes);
+EXPORT int celt_encode_float(CELTEncoder *st, const float *pcm, float *optional_synthesis, unsigned char *compressed, int nbCompressedBytes);
+EXPORT int celt_encode(CELTEncoder *st, const celt_int16_t *pcm, celt_int16_t *optional_synthesis, unsigned char *compressed, int nbCompressedBytes);
 
 /** Query and set encoder parameters 
  @param st Encoder state
@@ -161,7 +161,7 @@ EXPORT int celt_encode(CELTEncoder *st, celt_int16_t *pcm, unsigned char *compre
  @param value Pointer to a 32-bit int value
  @return Error code
 */
-EXPORT int celt_encoder_ctl(CELTEncoder * restrict st, int request, celt_int32_t *value);
+EXPORT int celt_encoder_ctl(CELTEncoder * st, int request, celt_int32_t *value);
 
 /* Decoder stuff */
 
diff --git a/libcelt/testcelt.c b/libcelt/testcelt.c
index f943d600..4dad6d12 100644
--- a/libcelt/testcelt.c
+++ b/libcelt/testcelt.c
@@ -111,7 +111,7 @@ int main(int argc, char *argv[])
       fread(in, sizeof(short), frame_size*channels, fin);
       if (feof(fin))
          break;
-      len = celt_encode(enc, in, data, bytes_per_packet);
+      len = celt_encode(enc, in, in, data, bytes_per_packet);
       if (len <= 0)
       {
          fprintf (stderr, "celt_encode() returned %d\n", len);
diff --git a/tools/celtclient.c b/tools/celtclient.c
index 39d27fbd..cdae9557 100644
--- a/tools/celtclient.c
+++ b/tools/celtclient.c
@@ -116,7 +116,7 @@ int main(int argc, char *argv[])
    }
 
    /* Setup audio device */
-   audio_dev = alsa_device_open(argv[1], SAMPLING_RATE, 1, FRAME_SIZE);
+   audio_dev = alsa_device_open(argv[1], SAMPLING_RATE, 2, FRAME_SIZE);
    
    /* Setup the encoder and decoder in wideband */
    CELTEncoder *enc_state;
@@ -210,7 +210,7 @@ int main(int argc, char *argv[])
             pcm[i] = pcm2[i];
          
          /* Encode */
-         celt_encode(enc_state, pcm, outpacket+4, packetSize);
+         celt_encode(enc_state, pcm, NULL, outpacket+4, packetSize);
          
          /* Pseudo header: four null bytes and a 32-bit timestamp */
          ((int*)outpacket)[0] = send_timestamp;
diff --git a/tools/celtenc.c b/tools/celtenc.c
index e8ecafbf..f6b1e5c3 100644
--- a/tools/celtenc.c
+++ b/tools/celtenc.c
@@ -598,7 +598,7 @@ int main(int argc, char **argv)
       id++;
       /*Encode current frame*/
 
-      nbBytes = celt_encode(st, input, bits, bytes_per_packet);
+      nbBytes = celt_encode(st, input, NULL, bits, bytes_per_packet);
       if (nbBytes<0)
       {
          fprintf(stderr, "Got error %d while encoding. Aborting.\n", nbBytes);