Move arch check before OS check.

[ffmpeg] / libavcodec / imc.c

diff --git a/libavcodec/imc.c b/libavcodec/imc.c
index d9db73599ca71a6285440c3e5140b446896f30de..12ce5953664acad46ded3fbb2975600f3b11c600 100644 (file)
--- a/libavcodec/imc.c
+++ b/libavcodec/imc.c
@@ -19,7 +19,6 @@
  * You should have received a copy of the GNU Lesser General Public
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- *
  */
 
 /**
@@ -42,6 +41,7 @@
 
 #include "imcdata.h"
 
+#define IMC_BLOCK_SIZE 64
 #define IMC_FRAME_ID 0x21
 #define BANDS 32
 #define COEFFS 256
@@ -80,7 +80,6 @@ typedef struct {
     float sqrt_tab[30];
     GetBitContext gb;
     VLC huffman_vlc[4][4];
-    float flcf1, flcf2;
     int decoder_reset;
     float one_div_log2;
 
@@ -91,7 +90,7 @@ typedef struct {
 } IMCContext;
 
 
-static int imc_decode_init(AVCodecContext * avctx)
+static av_cold int imc_decode_init(AVCodecContext * avctx)
 {
     int i, j;
     IMCContext *q = avctx->priv_data;
@@ -125,8 +124,6 @@ static int imc_decode_init(AVCodecContext * avctx)
 
         q->last_fft_im[i] = 0;
     }
-    q->flcf1 = log2(10) * 0.05703125;
-    q->flcf2 = log2(10) * 0.25;
 
     /* Generate a square root table */
 
@@ -236,8 +233,8 @@ static void imc_decode_level_coefficients(IMCContext* q, int* levlCoeffBuf, floa
     float tmp, tmp2;
     //maybe some frequency division thingy
 
-    flcoeffs1[0] = 20000.0 / pow (2, levlCoeffBuf[0] * q->flcf1);
-    flcoeffs2[0] = log2(flcoeffs1[0]);
+    flcoeffs1[0] = 20000.0 / pow (2, levlCoeffBuf[0] * 0.18945); // 0.18945 = log2(10) * 0.05703125
+    flcoeffs2[0] = log(flcoeffs1[0])/log(2);
     tmp = flcoeffs1[0];
     tmp2 = flcoeffs2[0];
 
@@ -255,7 +252,7 @@ static void imc_decode_level_coefficients(IMCContext* q, int* levlCoeffBuf, floa
                 level -=16;
 
             tmp  *= imc_exp_tab[15 + level];
-            tmp2 += q->flcf2 * level;
+            tmp2 += 0.83048 * level;  // 0.83048 = log2(10) * 0.25
             flcoeffs1[i] = tmp;
             flcoeffs2[i] = tmp2;
         }
@@ -273,7 +270,7 @@ static void imc_decode_level_coefficients2(IMCContext* q, int* levlCoeffBuf, flo
         flcoeffs1[i] = 0;
         if(levlCoeffBuf[i] < 16) {
             flcoeffs1[i] = imc_exp_tab2[levlCoeffBuf[i]] * old_floor[i];
-            flcoeffs2[i] = (levlCoeffBuf[i]-7) * q->flcf2 + flcoeffs2[i];
+            flcoeffs2[i] = (levlCoeffBuf[i]-7) * 0.83048 + flcoeffs2[i]; // 0.83048 = log2(10) * 0.25
         } else {
             flcoeffs1[i] = old_floor[i];
         }
@@ -304,7 +301,7 @@ static int bit_allocation (IMCContext* q, int stream_format_code, int freebits,
         highest = FFMAX(highest, q->flcoeffs1[i]);
 
     for(i = 0; i < BANDS-1; i++) {
-        q->flcoeffs4[i] = q->flcoeffs3[i] - log2(q->flcoeffs5[i]);
+        q->flcoeffs4[i] = q->flcoeffs3[i] - log(q->flcoeffs5[i])/log(2);
     }
     q->flcoeffs4[BANDS - 1] = limit;
 
@@ -350,7 +347,7 @@ static int bit_allocation (IMCContext* q, int stream_format_code, int freebits,
         iacc = 0;
 
         for(j = (stream_format_code & 0x2)?4:0; j < BANDS; j++) {
-            cwlen = clip((int)((q->flcoeffs4[j] * 0.5) - summa + 0.5), 0, 6);
+            cwlen = av_clip((int)((q->flcoeffs4[j] * 0.5) - summa + 0.5), 0, 6);
 
             q->bitsBandT[j] = cwlen;
             summer += q->bandWidthT[j] * cwlen;
@@ -458,7 +455,7 @@ static void imc_get_skip_coeff(IMCContext* q) {
             q->skipFlagBits[i] = band_tab[i+1] - band_tab[i];
 
             for(j = band_tab[i]; j < band_tab[i+1]; j++) {
-                if ((q->skipFlags[j] = get_bits(&q->gb,1)))
+                if ((q->skipFlags[j] = get_bits1(&q->gb)))
                     q->skipFlagCount[i]++;
             }
         } else {
@@ -489,7 +486,7 @@ static void imc_get_skip_coeff(IMCContext* q) {
 
             if (j < band_tab[i+1]) {
                 q->skipFlagBits[i]++;
-                if ((q->skipFlags[j] = get_bits(&q->gb,1)))
+                if ((q->skipFlags[j] = get_bits1(&q->gb)))
                     q->skipFlagCount[i]++;
             }
         }
@@ -629,7 +626,7 @@ static int imc_get_coeffs (IMCContext* q) {
 
 static int imc_decode_frame(AVCodecContext * avctx,
                             void *data, int *data_size,
-                            uint8_t * buf, int buf_size)
+                            const uint8_t * buf, int buf_size)
 {
 
     IMCContext *q = avctx->priv_data;
@@ -639,13 +636,16 @@ static int imc_decode_frame(AVCodecContext * avctx,
     int flag;
     int bits, summer;
     int counter, bitscount;
-    uint16_t *buf16 = (uint16_t *) buf;
+    uint16_t buf16[IMC_BLOCK_SIZE / 2];
 
-    /* FIXME: input should not be modified */
-    for(i = 0; i < FFMIN(buf_size, avctx->block_align) / 2; i++)
-        buf16[i] = bswap_16(buf16[i]);
+    if (buf_size < IMC_BLOCK_SIZE) {
+        av_log(avctx, AV_LOG_ERROR, "imc frame too small!\n");
+        return -1;
+    }
+    for(i = 0; i < IMC_BLOCK_SIZE / 2; i++)
+        buf16[i] = bswap_16(((const uint16_t*)buf)[i]);
 
-    init_get_bits(&q->gb, buf, 512);
+    init_get_bits(&q->gb, (const uint8_t*)buf16, IMC_BLOCK_SIZE * 8);
 
     /* Check the frame header */
     imc_hdr = get_bits(&q->gb, 9);
@@ -792,11 +792,11 @@ static int imc_decode_frame(AVCodecContext * avctx,
 
     *data_size = COEFFS * sizeof(int16_t);
 
-    return avctx->block_align;
+    return IMC_BLOCK_SIZE;
 }
 
 
-static int imc_decode_close(AVCodecContext * avctx)
+static av_cold int imc_decode_close(AVCodecContext * avctx)
 {
     IMCContext *q = avctx->priv_data;
 
@@ -813,4 +813,5 @@ AVCodec imc_decoder = {
     .init = imc_decode_init,
     .close = imc_decode_close,
     .decode = imc_decode_frame,
+    .long_name = "IMC (Intel Music Coder)",
 };