Add ASUS V1/V2 decoder codec long names.

[ffmpeg] / libavcodec / ac3enc.c

diff --git a/libavcodec/ac3enc.c b/libavcodec/ac3enc.c
index d90df530ffe0b48e5856572824b479bb0d6d4db6..e85d86c9018eefaf29be4f6f4f7de26eb90a33e5 100644 (file)
--- a/libavcodec/ac3enc.c
+++ b/libavcodec/ac3enc.c
@@ -25,9 +25,9 @@
  */
 //#define DEBUG
 //#define DEBUG_BITALLOC
+#include "libavutil/crc.h"
 #include "avcodec.h"
 #include "bitstream.h"
-#include "crc.h"
 #include "ac3.h"
 
 typedef struct AC3EncodeContext {
@@ -64,7 +64,6 @@ typedef struct AC3EncodeContext {
 
 static int16_t costab[64];
 static int16_t sintab[64];
-static int16_t fft_rev[512];
 static int16_t xcos1[128];
 static int16_t xsin1[128];
 
@@ -74,8 +73,6 @@ static int16_t xsin1[128];
 /* new exponents are sent if their Norm 1 exceed this number */
 #define EXP_DIFF_THRESHOLD 1000
 
-static void fft_init(int ln);
-
 static inline int16_t fix15(float a)
 {
     int v;
@@ -93,7 +90,7 @@ typedef struct IComplex {
 
 static void fft_init(int ln)
 {
-    int i, j, m, n;
+    int i, n;
     float alpha;
 
     n = 1 << ln;
@@ -103,14 +100,6 @@ static void fft_init(int ln)
         costab[i] = fix15(cos(alpha));
         sintab[i] = fix15(sin(alpha));
     }
-
-    for(i=0;i<n;i++) {
-        m=0;
-        for(j=0;j<ln;j++) {
-            m |= ((i >> j) & 1) << (ln-j-1);
-        }
-        fft_rev[i]=m;
-    }
 }
 
 /* butter fly op */
@@ -148,14 +137,9 @@ static void fft(IComplex *z, int ln)
 
     /* reverse */
     for(j=0;j<np;j++) {
-        int k;
-        IComplex tmp;
-        k = fft_rev[j];
-        if (k < j) {
-            tmp = z[k];
-            z[k] = z[j];
-            z[j] = tmp;
-        }
+        int k = ff_reverse[j] >> (8 - ln);
+        if (k < j)
+            FFSWAP(IComplex, z[k], z[j]);
     }
 
     /* pass 0 */
@@ -624,7 +608,7 @@ static int compute_bit_allocation(AC3EncodeContext *s,
     return 0;
 }
 
-static int AC3_encode_init(AVCodecContext *avctx)
+static av_cold int AC3_encode_init(AVCodecContext *avctx)
 {
     int freq = avctx->sample_rate;
     int bitrate = avctx->bit_rate;
@@ -632,6 +616,7 @@ static int AC3_encode_init(AVCodecContext *avctx)
     AC3EncodeContext *s = avctx->priv_data;
     int i, j, ch;
     float alpha;
+    int bw_code;
     static const uint8_t channel_mode_defs[6] = {
         0x01, /* C */
         0x02, /* L R */
@@ -669,9 +654,8 @@ static int AC3_encode_init(AVCodecContext *avctx)
     s->bitstream_mode = 0; /* complete main audio service */
 
     /* bitrate & frame size */
-    bitrate /= 1000;
     for(i=0;i<19;i++) {
-        if ((ff_ac3_bitrate_tab[i] >> s->sr_shift) == bitrate)
+        if ((ff_ac3_bitrate_tab[i] >> s->sr_shift)*1000 == bitrate)
             break;
     }
     if (i == 19)
@@ -684,12 +668,21 @@ static int AC3_encode_init(AVCodecContext *avctx)
     s->frame_size = s->frame_size_min;
 
     /* bit allocation init */
+    if(avctx->cutoff) {
+        /* calculate bandwidth based on user-specified cutoff frequency */
+        int cutoff = av_clip(avctx->cutoff, 1, s->sample_rate >> 1);
+        int fbw_coeffs = cutoff * 512 / s->sample_rate;
+        bw_code = av_clip((fbw_coeffs - 73) / 3, 0, 60);
+    } else {
+        /* use default bandwidth setting */
+        /* XXX: should compute the bandwidth according to the frame
+           size, so that we avoid annoying high frequency artifacts */
+        bw_code = 50;
+    }
     for(ch=0;ch<s->nb_channels;ch++) {
         /* bandwidth for each channel */
-        /* XXX: should compute the bandwidth according to the frame
-           size, so that we avoid anoying high freq artefacts */
-        s->chbwcod[ch] = 50; /* sample bandwidth as mpeg audio layer 2 table 0 */
-        s->nb_coefs[ch] = ((s->chbwcod[ch] + 12) * 3) + 37;
+        s->chbwcod[ch] = bw_code;
+        s->nb_coefs[ch] = bw_code * 3 + 73;
     }
     if (s->lfe) {
         s->nb_coefs[s->lfe_channel] = 7; /* fixed */
@@ -1132,13 +1125,16 @@ static int output_frame_end(AC3EncodeContext *s)
     /* Now we must compute both crcs : this is not so easy for crc1
        because it is at the beginning of the data... */
     frame_size_58 = (frame_size >> 1) + (frame_size >> 3);
-    crc1 = bswap_16(av_crc(av_crc8005, 0, frame + 4, 2 * frame_size_58 - 4));
+    crc1 = bswap_16(av_crc(av_crc_get_table(AV_CRC_16_ANSI), 0,
+                           frame + 4, 2 * frame_size_58 - 4));
     /* XXX: could precompute crc_inv */
     crc_inv = pow_poly((CRC16_POLY >> 1), (16 * frame_size_58) - 16, CRC16_POLY);
     crc1 = mul_poly(crc_inv, crc1, CRC16_POLY);
     AV_WB16(frame+2,crc1);
 
-    crc2 = bswap_16(av_crc(av_crc8005, 0, frame + 2 * frame_size_58, (frame_size - frame_size_58) * 2 - 2));
+    crc2 = bswap_16(av_crc(av_crc_get_table(AV_CRC_16_ANSI), 0,
+                           frame + 2 * frame_size_58,
+                           (frame_size - frame_size_58) * 2 - 2));
     AV_WB16(frame+2*frame_size-2,crc2);
 
     //    printf("n=%d frame_size=%d\n", n, frame_size);
@@ -1240,11 +1236,11 @@ static int AC3_encode_frame(AVCodecContext *avctx,
     }
 
     /* adjust for fractional frame sizes */
-    while(s->bits_written >= s->bit_rate*1000 && s->samples_written >= s->sample_rate) {
-        s->bits_written -= s->bit_rate*1000;
+    while(s->bits_written >= s->bit_rate && s->samples_written >= s->sample_rate) {
+        s->bits_written -= s->bit_rate;
         s->samples_written -= s->sample_rate;
     }
-    s->frame_size = s->frame_size_min + (s->bits_written * s->sample_rate < s->samples_written * s->bit_rate*1000);
+    s->frame_size = s->frame_size_min + (s->bits_written * s->sample_rate < s->samples_written * s->bit_rate);
     s->bits_written += s->frame_size * 16;
     s->samples_written += AC3_FRAME_SIZE;
 
@@ -1259,7 +1255,7 @@ static int AC3_encode_frame(AVCodecContext *avctx,
     return output_frame_end(s);
 }
 
-static int AC3_encode_close(AVCodecContext *avctx)
+static av_cold int AC3_encode_close(AVCodecContext *avctx)
 {
     av_freep(&avctx->coded_frame);
     return 0;
@@ -1367,4 +1363,5 @@ AVCodec ac3_encoder = {
     AC3_encode_frame,
     AC3_encode_close,
     NULL,
+    .long_name = "ATSC A/52 / AC-3",
 };