wma encoder

Originally committed as revision 7855 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 386 insertions, 0 deletions

diff --git a/libavcodec/wma.c b/libavcodec/wma.c
new file mode 100644
index 0000000000..31a417ac51
--- /dev/null
+++ b/libavcodec/wma.c
@@ -0,0 +1,386 @@
+/*
+ * WMA compatible codec
+ * Copyright (c) 2002-2007 The FFmpeg Project.
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * 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
+ */
+
+#include "avcodec.h"
+#include "wma.h"
+#include "wmadata.h"
+
+#undef NDEBUG
+#include <assert.h>
+
+/* XXX: use same run/length optimization as mpeg decoders */
+//FIXME maybe split decode / encode or pass flag
+static void init_coef_vlc(VLC *vlc,
+                          uint16_t **prun_table, uint16_t **plevel_table, uint16_t **pint_table,
+                          const CoefVLCTable *vlc_table)
+{
+    int n = vlc_table->n;
+    const uint8_t *table_bits = vlc_table->huffbits;
+    const uint32_t *table_codes = vlc_table->huffcodes;
+    const uint16_t *levels_table = vlc_table->levels;
+    uint16_t *run_table, *level_table, *int_table;
+    int i, l, j, k, level;
+
+    init_vlc(vlc, VLCBITS, n, table_bits, 1, 1, table_codes, 4, 4, 0);
+
+    run_table = av_malloc(n * sizeof(uint16_t));
+    level_table = av_malloc(n * sizeof(uint16_t));
+    int_table = av_malloc(n * sizeof(uint16_t));
+    i = 2;
+    level = 1;
+    k = 0;
+    while (i < n) {
+        int_table[k]= i;
+        l = levels_table[k++];
+        for(j=0;j<l;j++) {
+            run_table[i] = j;
+            level_table[i] = level;
+            i++;
+        }
+        level++;
+    }
+    *prun_table = run_table;
+    *plevel_table = level_table;
+    *pint_table= int_table;
+}
+
+int ff_wma_init(AVCodecContext * avctx, int flags2)
+{
+    WMADecodeContext *s = avctx->priv_data;
+    int i;
+    float *window;
+    float bps1, high_freq;
+    volatile float bps;
+    int sample_rate1;
+    int coef_vlc_table;
+
+    s->sample_rate = avctx->sample_rate;
+    s->nb_channels = avctx->channels;
+    s->bit_rate = avctx->bit_rate;
+    s->block_align = avctx->block_align;
+
+    dsputil_init(&s->dsp, avctx);
+
+    if (avctx->codec->id == CODEC_ID_WMAV1) {
+        s->version = 1;
+    } else {
+        s->version = 2;
+    }
+
+    /* compute MDCT block size */
+    if (s->sample_rate <= 16000) {
+        s->frame_len_bits = 9;
+    } else if (s->sample_rate <= 22050 ||
+               (s->sample_rate <= 32000 && s->version == 1)) {
+        s->frame_len_bits = 10;
+    } else {
+        s->frame_len_bits = 11;
+    }
+    s->frame_len = 1 << s->frame_len_bits;
+    if (s->use_variable_block_len) {
+        int nb_max, nb;
+        nb = ((flags2 >> 3) & 3) + 1;
+        if ((s->bit_rate / s->nb_channels) >= 32000)
+            nb += 2;
+        nb_max = s->frame_len_bits - BLOCK_MIN_BITS;
+        if (nb > nb_max)
+            nb = nb_max;
+        s->nb_block_sizes = nb + 1;
+    } else {
+        s->nb_block_sizes = 1;
+    }
+
+    /* init rate dependant parameters */
+    s->use_noise_coding = 1;
+    high_freq = s->sample_rate * 0.5;
+
+    /* if version 2, then the rates are normalized */
+    sample_rate1 = s->sample_rate;
+    if (s->version == 2) {
+        if (sample_rate1 >= 44100)
+            sample_rate1 = 44100;
+        else if (sample_rate1 >= 22050)
+            sample_rate1 = 22050;
+        else if (sample_rate1 >= 16000)
+            sample_rate1 = 16000;
+        else if (sample_rate1 >= 11025)
+            sample_rate1 = 11025;
+        else if (sample_rate1 >= 8000)
+            sample_rate1 = 8000;
+    }
+
+    bps = (float)s->bit_rate / (float)(s->nb_channels * s->sample_rate);
+    s->byte_offset_bits = av_log2((int)(bps * s->frame_len / 8.0 + 0.5)) + 2;
+
+    /* compute high frequency value and choose if noise coding should
+       be activated */
+    bps1 = bps;
+    if (s->nb_channels == 2)
+        bps1 = bps * 1.6;
+    if (sample_rate1 == 44100) {
+        if (bps1 >= 0.61)
+            s->use_noise_coding = 0;
+        else
+            high_freq = high_freq * 0.4;
+    } else if (sample_rate1 == 22050) {
+        if (bps1 >= 1.16)
+            s->use_noise_coding = 0;
+        else if (bps1 >= 0.72)
+            high_freq = high_freq * 0.7;
+        else
+            high_freq = high_freq * 0.6;
+    } else if (sample_rate1 == 16000) {
+        if (bps > 0.5)
+            high_freq = high_freq * 0.5;
+        else
+            high_freq = high_freq * 0.3;
+    } else if (sample_rate1 == 11025) {
+        high_freq = high_freq * 0.7;
+    } else if (sample_rate1 == 8000) {
+        if (bps <= 0.625) {
+            high_freq = high_freq * 0.5;
+        } else if (bps > 0.75) {
+            s->use_noise_coding = 0;
+        } else {
+            high_freq = high_freq * 0.65;
+        }
+    } else {
+        if (bps >= 0.8) {
+            high_freq = high_freq * 0.75;
+        } else if (bps >= 0.6) {
+            high_freq = high_freq * 0.6;
+        } else {
+            high_freq = high_freq * 0.5;
+        }
+    }
+    dprintf("flags1=0x%x flags2=0x%x\n", flags1, flags2);
+    dprintf("version=%d channels=%d sample_rate=%d bitrate=%d block_align=%d\n",
+           s->version, s->nb_channels, s->sample_rate, s->bit_rate,
+           s->block_align);
+    dprintf("bps=%f bps1=%f high_freq=%f bitoffset=%d\n",
+           bps, bps1, high_freq, s->byte_offset_bits);
+    dprintf("use_noise_coding=%d use_exp_vlc=%d nb_block_sizes=%d\n",
+           s->use_noise_coding, s->use_exp_vlc, s->nb_block_sizes);
+
+    /* compute the scale factor band sizes for each MDCT block size */
+    {
+        int a, b, pos, lpos, k, block_len, i, j, n;
+        const uint8_t *table;
+
+        if (s->version == 1) {
+            s->coefs_start = 3;
+        } else {
+            s->coefs_start = 0;
+        }
+        for(k = 0; k < s->nb_block_sizes; k++) {
+            block_len = s->frame_len >> k;
+
+            if (s->version == 1) {
+                lpos = 0;
+                for(i=0;i<25;i++) {
+                    a = wma_critical_freqs[i];
+                    b = s->sample_rate;
+                    pos = ((block_len * 2 * a)  + (b >> 1)) / b;
+                    if (pos > block_len)
+                        pos = block_len;
+                    s->exponent_bands[0][i] = pos - lpos;
+                    if (pos >= block_len) {
+                        i++;
+                        break;
+                    }
+                    lpos = pos;
+                }
+                s->exponent_sizes[0] = i;
+            } else {
+                /* hardcoded tables */
+                table = NULL;
+                a = s->frame_len_bits - BLOCK_MIN_BITS - k;
+                if (a < 3) {
+                    if (s->sample_rate >= 44100)
+                        table = exponent_band_44100[a];
+                    else if (s->sample_rate >= 32000)
+                        table = exponent_band_32000[a];
+                    else if (s->sample_rate >= 22050)
+                        table = exponent_band_22050[a];
+                }
+                if (table) {
+                    n = *table++;
+                    for(i=0;i<n;i++)
+                        s->exponent_bands[k][i] = table[i];
+                    s->exponent_sizes[k] = n;
+                } else {
+                    j = 0;
+                    lpos = 0;
+                    for(i=0;i<25;i++) {
+                        a = wma_critical_freqs[i];
+                        b = s->sample_rate;
+                        pos = ((block_len * 2 * a)  + (b << 1)) / (4 * b);
+                        pos <<= 2;
+                        if (pos > block_len)
+                            pos = block_len;
+                        if (pos > lpos)
+                            s->exponent_bands[k][j++] = pos - lpos;
+                        if (pos >= block_len)
+                            break;
+                        lpos = pos;
+                    }
+                    s->exponent_sizes[k] = j;
+                }
+            }
+
+            /* max number of coefs */
+            s->coefs_end[k] = (s->frame_len - ((s->frame_len * 9) / 100)) >> k;
+            /* high freq computation */
+            s->high_band_start[k] = (int)((block_len * 2 * high_freq) /
+                                          s->sample_rate + 0.5);
+            n = s->exponent_sizes[k];
+            j = 0;
+            pos = 0;
+            for(i=0;i<n;i++) {
+                int start, end;
+                start = pos;
+                pos += s->exponent_bands[k][i];
+                end = pos;
+                if (start < s->high_band_start[k])
+                    start = s->high_band_start[k];
+                if (end > s->coefs_end[k])
+                    end = s->coefs_end[k];
+                if (end > start)
+                    s->exponent_high_bands[k][j++] = end - start;
+            }
+            s->exponent_high_sizes[k] = j;
+#if 0
+            tprintf("%5d: coefs_end=%d high_band_start=%d nb_high_bands=%d: ",
+                  s->frame_len >> k,
+                  s->coefs_end[k],
+                  s->high_band_start[k],
+                  s->exponent_high_sizes[k]);
+            for(j=0;j<s->exponent_high_sizes[k];j++)
+                tprintf(" %d", s->exponent_high_bands[k][j]);
+            tprintf("\n");
+#endif
+        }
+    }
+
+#ifdef TRACE
+    {
+        int i, j;
+        for(i = 0; i < s->nb_block_sizes; i++) {
+            tprintf("%5d: n=%2d:",
+                   s->frame_len >> i,
+                   s->exponent_sizes[i]);
+            for(j=0;j<s->exponent_sizes[i];j++)
+                tprintf(" %d", s->exponent_bands[i][j]);
+            tprintf("\n");
+        }
+    }
+#endif
+
+    /* init MDCT windows : simple sinus window */
+    for(i = 0; i < s->nb_block_sizes; i++) {
+        int n, j;
+        float alpha;
+        n = 1 << (s->frame_len_bits - i);
+        window = av_malloc(sizeof(float) * n);
+        alpha = M_PI / (2.0 * n);
+        for(j=0;j<n;j++) {
+            window[n - j - 1] = sin((j + 0.5) * alpha);
+        }
+        s->windows[i] = window;
+    }
+
+    s->reset_block_lengths = 1;
+
+    if (s->use_noise_coding) {
+
+        /* init the noise generator */
+        if (s->use_exp_vlc)
+            s->noise_mult = 0.02;
+        else
+            s->noise_mult = 0.04;
+
+#ifdef TRACE
+        for(i=0;i<NOISE_TAB_SIZE;i++)
+            s->noise_table[i] = 1.0 * s->noise_mult;
+#else
+        {
+            unsigned int seed;
+            float norm;
+            seed = 1;
+            norm = (1.0 / (float)(1LL << 31)) * sqrt(3) * s->noise_mult;
+            for(i=0;i<NOISE_TAB_SIZE;i++) {
+                seed = seed * 314159 + 1;
+                s->noise_table[i] = (float)((int)seed) * norm;
+            }
+        }
+#endif
+    }
+
+    /* choose the VLC tables for the coefficients */
+    coef_vlc_table = 2;
+    if (s->sample_rate >= 32000) {
+        if (bps1 < 0.72)
+            coef_vlc_table = 0;
+        else if (bps1 < 1.16)
+            coef_vlc_table = 1;
+    }
+    s->coef_vlcs[0]= &coef_vlcs[coef_vlc_table * 2    ];
+    s->coef_vlcs[1]= &coef_vlcs[coef_vlc_table * 2 + 1];
+    init_coef_vlc(&s->coef_vlc[0], &s->run_table[0], &s->level_table[0], &s->int_table[0],
+                  s->coef_vlcs[0]);
+    init_coef_vlc(&s->coef_vlc[1], &s->run_table[1], &s->level_table[1], &s->int_table[1],
+                  s->coef_vlcs[1]);
+
+    return 0;
+}
+
+int ff_wma_total_gain_to_bits(int total_gain){
+         if (total_gain < 15) return 13;
+    else if (total_gain < 32) return 12;
+    else if (total_gain < 40) return 11;
+    else if (total_gain < 45) return 10;
+    else                      return  9;
+}
+
+int ff_wma_end(AVCodecContext *avctx)
+{
+    WMADecodeContext *s = avctx->priv_data;
+    int i;
+
+    for(i = 0; i < s->nb_block_sizes; i++)
+        ff_mdct_end(&s->mdct_ctx[i]);
+    for(i = 0; i < s->nb_block_sizes; i++)
+        av_free(s->windows[i]);
+
+    if (s->use_exp_vlc) {
+        free_vlc(&s->exp_vlc);
+    }
+    if (s->use_noise_coding) {
+        free_vlc(&s->hgain_vlc);
+    }
+    for(i = 0;i < 2; i++) {
+        free_vlc(&s->coef_vlc[i]);
+        av_free(s->run_table[i]);
+        av_free(s->level_table[i]);
+    }
+
+    return 0;
+}