yading@10: /*
yading@10:  * Bink Audio decoder
yading@10:  * Copyright (c) 2007-2011 Peter Ross (pross@xvid.org)
yading@10:  * Copyright (c) 2009 Daniel Verkamp (daniel@drv.nu)
yading@10:  *
yading@10:  * This file is part of FFmpeg.
yading@10:  *
yading@10:  * FFmpeg is free software; you can redistribute it and/or
yading@10:  * modify it under the terms of the GNU Lesser General Public
yading@10:  * License as published by the Free Software Foundation; either
yading@10:  * version 2.1 of the License, or (at your option) any later version.
yading@10:  *
yading@10:  * FFmpeg is distributed in the hope that it will be useful,
yading@10:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@10:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@10:  * Lesser General Public License for more details.
yading@10:  *
yading@10:  * You should have received a copy of the GNU Lesser General Public
yading@10:  * License along with FFmpeg; if not, write to the Free Software
yading@10:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@10:  */
yading@10: 
yading@10: /**
yading@10:  * @file
yading@10:  * Bink Audio decoder
yading@10:  *
yading@10:  * Technical details here:
yading@10:  *  http://wiki.multimedia.cx/index.php?title=Bink_Audio
yading@10:  */
yading@10: 
yading@10: #include "libavutil/channel_layout.h"
yading@10: #include "avcodec.h"
yading@10: #define BITSTREAM_READER_LE
yading@10: #include "get_bits.h"
yading@10: #include "dct.h"
yading@10: #include "rdft.h"
yading@10: #include "fmtconvert.h"
yading@10: #include "internal.h"
yading@10: #include "libavutil/intfloat.h"
yading@10: 
yading@10: extern const uint16_t ff_wma_critical_freqs[25];
yading@10: 
yading@10: static float quant_table[96];
yading@10: 
yading@10: #define MAX_CHANNELS 2
yading@10: #define BINK_BLOCK_MAX_SIZE (MAX_CHANNELS << 11)
yading@10: 
yading@10: typedef struct {
yading@10:     GetBitContext gb;
yading@10:     int version_b;          ///< Bink version 'b'
yading@10:     int first;
yading@10:     int channels;
yading@10:     int frame_len;          ///< transform size (samples)
yading@10:     int overlap_len;        ///< overlap size (samples)
yading@10:     int block_size;
yading@10:     int num_bands;
yading@10:     unsigned int *bands;
yading@10:     float root;
yading@10:     DECLARE_ALIGNED(32, FFTSample, coeffs)[BINK_BLOCK_MAX_SIZE];
yading@10:     float previous[MAX_CHANNELS][BINK_BLOCK_MAX_SIZE / 16];  ///< coeffs from previous audio block
yading@10:     uint8_t *packet_buffer;
yading@10:     union {
yading@10:         RDFTContext rdft;
yading@10:         DCTContext dct;
yading@10:     } trans;
yading@10: } BinkAudioContext;
yading@10: 
yading@10: 
yading@10: static av_cold int decode_init(AVCodecContext *avctx)
yading@10: {
yading@10:     BinkAudioContext *s = avctx->priv_data;
yading@10:     int sample_rate = avctx->sample_rate;
yading@10:     int sample_rate_half;
yading@10:     int i;
yading@10:     int frame_len_bits;
yading@10: 
yading@10:     /* determine frame length */
yading@10:     if (avctx->sample_rate < 22050) {
yading@10:         frame_len_bits = 9;
yading@10:     } else if (avctx->sample_rate < 44100) {
yading@10:         frame_len_bits = 10;
yading@10:     } else {
yading@10:         frame_len_bits = 11;
yading@10:     }
yading@10: 
yading@10:     if (avctx->channels < 1 || avctx->channels > MAX_CHANNELS) {
yading@10:         av_log(avctx, AV_LOG_ERROR, "invalid number of channels: %d\n", avctx->channels);
yading@10:         return AVERROR_INVALIDDATA;
yading@10:     }
yading@10:     avctx->channel_layout = avctx->channels == 1 ? AV_CH_LAYOUT_MONO :
yading@10:                                                    AV_CH_LAYOUT_STEREO;
yading@10: 
yading@10:     s->version_b = avctx->extradata_size >= 4 && avctx->extradata[3] == 'b';
yading@10: 
yading@10:     if (avctx->codec->id == AV_CODEC_ID_BINKAUDIO_RDFT) {
yading@10:         // audio is already interleaved for the RDFT format variant
yading@10:         avctx->sample_fmt = AV_SAMPLE_FMT_FLT;
yading@10:         sample_rate  *= avctx->channels;
yading@10:         s->channels = 1;
yading@10:         if (!s->version_b)
yading@10:             frame_len_bits += av_log2(avctx->channels);
yading@10:     } else {
yading@10:         s->channels = avctx->channels;
yading@10:         avctx->sample_fmt = AV_SAMPLE_FMT_FLTP;
yading@10:     }
yading@10: 
yading@10:     s->frame_len     = 1 << frame_len_bits;
yading@10:     s->overlap_len   = s->frame_len / 16;
yading@10:     s->block_size    = (s->frame_len - s->overlap_len) * s->channels;
yading@10:     sample_rate_half = (sample_rate + 1) / 2;
yading@10:     if (avctx->codec->id == AV_CODEC_ID_BINKAUDIO_RDFT)
yading@10:         s->root = 2.0 / (sqrt(s->frame_len) * 32768.0);
yading@10:     else
yading@10:         s->root = s->frame_len / (sqrt(s->frame_len) * 32768.0);
yading@10:     for (i = 0; i < 96; i++) {
yading@10:         /* constant is result of 0.066399999/log10(M_E) */
yading@10:         quant_table[i] = expf(i * 0.15289164787221953823f) * s->root;
yading@10:     }
yading@10: 
yading@10:     /* calculate number of bands */
yading@10:     for (s->num_bands = 1; s->num_bands < 25; s->num_bands++)
yading@10:         if (sample_rate_half <= ff_wma_critical_freqs[s->num_bands - 1])
yading@10:             break;
yading@10: 
yading@10:     s->bands = av_malloc((s->num_bands + 1) * sizeof(*s->bands));
yading@10:     if (!s->bands)
yading@10:         return AVERROR(ENOMEM);
yading@10: 
yading@10:     /* populate bands data */
yading@10:     s->bands[0] = 2;
yading@10:     for (i = 1; i < s->num_bands; i++)
yading@10:         s->bands[i] = (ff_wma_critical_freqs[i - 1] * s->frame_len / sample_rate_half) & ~1;
yading@10:     s->bands[s->num_bands] = s->frame_len;
yading@10: 
yading@10:     s->first = 1;
yading@10: 
yading@10:     if (CONFIG_BINKAUDIO_RDFT_DECODER && avctx->codec->id == AV_CODEC_ID_BINKAUDIO_RDFT)
yading@10:         ff_rdft_init(&s->trans.rdft, frame_len_bits, DFT_C2R);
yading@10:     else if (CONFIG_BINKAUDIO_DCT_DECODER)
yading@10:         ff_dct_init(&s->trans.dct, frame_len_bits, DCT_III);
yading@10:     else
yading@10:         return -1;
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static float get_float(GetBitContext *gb)
yading@10: {
yading@10:     int power = get_bits(gb, 5);
yading@10:     float f = ldexpf(get_bits_long(gb, 23), power - 23);
yading@10:     if (get_bits1(gb))
yading@10:         f = -f;
yading@10:     return f;
yading@10: }
yading@10: 
yading@10: static const uint8_t rle_length_tab[16] = {
yading@10:     2, 3, 4, 5, 6, 8, 9, 10, 11, 12, 13, 14, 15, 16, 32, 64
yading@10: };
yading@10: 
yading@10: /**
yading@10:  * Decode Bink Audio block
yading@10:  * @param[out] out Output buffer (must contain s->block_size elements)
yading@10:  * @return 0 on success, negative error code on failure
yading@10:  */
yading@10: static int decode_block(BinkAudioContext *s, float **out, int use_dct)
yading@10: {
yading@10:     int ch, i, j, k;
yading@10:     float q, quant[25];
yading@10:     int width, coeff;
yading@10:     GetBitContext *gb = &s->gb;
yading@10: 
yading@10:     if (use_dct)
yading@10:         skip_bits(gb, 2);
yading@10: 
yading@10:     for (ch = 0; ch < s->channels; ch++) {
yading@10:         FFTSample *coeffs = out[ch];
yading@10: 
yading@10:         if (s->version_b) {
yading@10:             if (get_bits_left(gb) < 64)
yading@10:                 return AVERROR_INVALIDDATA;
yading@10:             coeffs[0] = av_int2float(get_bits_long(gb, 32)) * s->root;
yading@10:             coeffs[1] = av_int2float(get_bits_long(gb, 32)) * s->root;
yading@10:         } else {
yading@10:             if (get_bits_left(gb) < 58)
yading@10:                 return AVERROR_INVALIDDATA;
yading@10:             coeffs[0] = get_float(gb) * s->root;
yading@10:             coeffs[1] = get_float(gb) * s->root;
yading@10:         }
yading@10: 
yading@10:         if (get_bits_left(gb) < s->num_bands * 8)
yading@10:             return AVERROR_INVALIDDATA;
yading@10:         for (i = 0; i < s->num_bands; i++) {
yading@10:             int value = get_bits(gb, 8);
yading@10:             quant[i]  = quant_table[FFMIN(value, 95)];
yading@10:         }
yading@10: 
yading@10:         k = 0;
yading@10:         q = quant[0];
yading@10: 
yading@10:         // parse coefficients
yading@10:         i = 2;
yading@10:         while (i < s->frame_len) {
yading@10:             if (s->version_b) {
yading@10:                 j = i + 16;
yading@10:             } else {
yading@10:                 int v = get_bits1(gb);
yading@10:                 if (v) {
yading@10:                     v = get_bits(gb, 4);
yading@10:                     j = i + rle_length_tab[v] * 8;
yading@10:                 } else {
yading@10:                     j = i + 8;
yading@10:                 }
yading@10:             }
yading@10: 
yading@10:             j = FFMIN(j, s->frame_len);
yading@10: 
yading@10:             width = get_bits(gb, 4);
yading@10:             if (width == 0) {
yading@10:                 memset(coeffs + i, 0, (j - i) * sizeof(*coeffs));
yading@10:                 i = j;
yading@10:                 while (s->bands[k] < i)
yading@10:                     q = quant[k++];
yading@10:             } else {
yading@10:                 while (i < j) {
yading@10:                     if (s->bands[k] == i)
yading@10:                         q = quant[k++];
yading@10:                     coeff = get_bits(gb, width);
yading@10:                     if (coeff) {
yading@10:                         int v;
yading@10:                         v = get_bits1(gb);
yading@10:                         if (v)
yading@10:                             coeffs[i] = -q * coeff;
yading@10:                         else
yading@10:                             coeffs[i] =  q * coeff;
yading@10:                     } else {
yading@10:                         coeffs[i] = 0.0f;
yading@10:                     }
yading@10:                     i++;
yading@10:                 }
yading@10:             }
yading@10:         }
yading@10: 
yading@10:         if (CONFIG_BINKAUDIO_DCT_DECODER && use_dct) {
yading@10:             coeffs[0] /= 0.5;
yading@10:             s->trans.dct.dct_calc(&s->trans.dct,  coeffs);
yading@10:         }
yading@10:         else if (CONFIG_BINKAUDIO_RDFT_DECODER)
yading@10:             s->trans.rdft.rdft_calc(&s->trans.rdft, coeffs);
yading@10:     }
yading@10: 
yading@10:     for (ch = 0; ch < s->channels; ch++) {
yading@10:         int j;
yading@10:         int count = s->overlap_len * s->channels;
yading@10:         if (!s->first) {
yading@10:             j = ch;
yading@10:             for (i = 0; i < s->overlap_len; i++, j += s->channels)
yading@10:                 out[ch][i] = (s->previous[ch][i] * (count - j) +
yading@10:                                       out[ch][i] *          j) / count;
yading@10:         }
yading@10:         memcpy(s->previous[ch], &out[ch][s->frame_len - s->overlap_len],
yading@10:                s->overlap_len * sizeof(*s->previous[ch]));
yading@10:     }
yading@10: 
yading@10:     s->first = 0;
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static av_cold int decode_end(AVCodecContext *avctx)
yading@10: {
yading@10:     BinkAudioContext * s = avctx->priv_data;
yading@10:     av_freep(&s->bands);
yading@10:     av_freep(&s->packet_buffer);
yading@10:     if (CONFIG_BINKAUDIO_RDFT_DECODER && avctx->codec->id == AV_CODEC_ID_BINKAUDIO_RDFT)
yading@10:         ff_rdft_end(&s->trans.rdft);
yading@10:     else if (CONFIG_BINKAUDIO_DCT_DECODER)
yading@10:         ff_dct_end(&s->trans.dct);
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static void get_bits_align32(GetBitContext *s)
yading@10: {
yading@10:     int n = (-get_bits_count(s)) & 31;
yading@10:     if (n) skip_bits(s, n);
yading@10: }
yading@10: 
yading@10: static int decode_frame(AVCodecContext *avctx, void *data,
yading@10:                         int *got_frame_ptr, AVPacket *avpkt)
yading@10: {
yading@10:     BinkAudioContext *s = avctx->priv_data;
yading@10:     AVFrame *frame      = data;
yading@10:     GetBitContext *gb = &s->gb;
yading@10:     int ret, consumed = 0;
yading@10: 
yading@10:     if (!get_bits_left(gb)) {
yading@10:         uint8_t *buf;
yading@10:         /* handle end-of-stream */
yading@10:         if (!avpkt->size) {
yading@10:             *got_frame_ptr = 0;
yading@10:             return 0;
yading@10:         }
yading@10:         if (avpkt->size < 4) {
yading@10:             av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
yading@10:             return AVERROR_INVALIDDATA;
yading@10:         }
yading@10:         buf = av_realloc(s->packet_buffer, avpkt->size + FF_INPUT_BUFFER_PADDING_SIZE);
yading@10:         if (!buf)
yading@10:             return AVERROR(ENOMEM);
yading@10:         s->packet_buffer = buf;
yading@10:         memcpy(s->packet_buffer, avpkt->data, avpkt->size);
yading@10:         init_get_bits(gb, s->packet_buffer, avpkt->size * 8);
yading@10:         consumed = avpkt->size;
yading@10: 
yading@10:         /* skip reported size */
yading@10:         skip_bits_long(gb, 32);
yading@10:     }
yading@10: 
yading@10:     /* get output buffer */
yading@10:     frame->nb_samples = s->frame_len;
yading@10:     if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
yading@10:         return ret;
yading@10: 
yading@10:     if (decode_block(s, (float **)frame->extended_data,
yading@10:                      avctx->codec->id == AV_CODEC_ID_BINKAUDIO_DCT)) {
yading@10:         av_log(avctx, AV_LOG_ERROR, "Incomplete packet\n");
yading@10:         return AVERROR_INVALIDDATA;
yading@10:     }
yading@10:     get_bits_align32(gb);
yading@10: 
yading@10:     frame->nb_samples = s->block_size / avctx->channels;
yading@10:     *got_frame_ptr    = 1;
yading@10: 
yading@10:     return consumed;
yading@10: }
yading@10: 
yading@10: AVCodec ff_binkaudio_rdft_decoder = {
yading@10:     .name           = "binkaudio_rdft",
yading@10:     .type           = AVMEDIA_TYPE_AUDIO,
yading@10:     .id             = AV_CODEC_ID_BINKAUDIO_RDFT,
yading@10:     .priv_data_size = sizeof(BinkAudioContext),
yading@10:     .init           = decode_init,
yading@10:     .close          = decode_end,
yading@10:     .decode         = decode_frame,
yading@10:     .capabilities   = CODEC_CAP_DELAY | CODEC_CAP_DR1,
yading@10:     .long_name      = NULL_IF_CONFIG_SMALL("Bink Audio (RDFT)")
yading@10: };
yading@10: 
yading@10: AVCodec ff_binkaudio_dct_decoder = {
yading@10:     .name           = "binkaudio_dct",
yading@10:     .type           = AVMEDIA_TYPE_AUDIO,
yading@10:     .id             = AV_CODEC_ID_BINKAUDIO_DCT,
yading@10:     .priv_data_size = sizeof(BinkAudioContext),
yading@10:     .init           = decode_init,
yading@10:     .close          = decode_end,
yading@10:     .decode         = decode_frame,
yading@10:     .capabilities   = CODEC_CAP_DELAY | CODEC_CAP_DR1,
yading@10:     .long_name      = NULL_IF_CONFIG_SMALL("Bink Audio (DCT)")
yading@10: };