1/*
2 * Bink Audio decoder
3 * Copyright (c) 2007-2011 Peter Ross (pross@xvid.org)
4 * Copyright (c) 2009 Daniel Verkamp (daniel@drv.nu)
5 *
6 * This file is part of FFmpeg.
7 *
8 * FFmpeg is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
12 *
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16 * Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23/**
24 * @file
25 * Bink Audio decoder
26 *
27 * Technical details here:
28 *  http://wiki.multimedia.cx/index.php?title=Bink_Audio
29 */
30
31#include "libavutil/channel_layout.h"
32#include "avcodec.h"
33#define BITSTREAM_READER_LE
34#include "get_bits.h"
35#include "dct.h"
36#include "rdft.h"
37#include "fmtconvert.h"
38#include "internal.h"
39#include "wma.h"
40#include "libavutil/intfloat.h"
41
42static float quant_table[96];
43
44#define MAX_CHANNELS 2
45#define BINK_BLOCK_MAX_SIZE (MAX_CHANNELS << 11)
46
47typedef struct {
48    GetBitContext gb;
49    int version_b;          ///< Bink version 'b'
50    int first;
51    int channels;
52    int frame_len;          ///< transform size (samples)
53    int overlap_len;        ///< overlap size (samples)
54    int block_size;
55    int num_bands;
56    unsigned int *bands;
57    float root;
58    DECLARE_ALIGNED(32, FFTSample, coeffs)[BINK_BLOCK_MAX_SIZE];
59    float previous[MAX_CHANNELS][BINK_BLOCK_MAX_SIZE / 16];  ///< coeffs from previous audio block
60    uint8_t *packet_buffer;
61    union {
62        RDFTContext rdft;
63        DCTContext dct;
64    } trans;
65} BinkAudioContext;
66
67
68static av_cold int decode_init(AVCodecContext *avctx)
69{
70    BinkAudioContext *s = avctx->priv_data;
71    int sample_rate = avctx->sample_rate;
72    int sample_rate_half;
73    int i;
74    int frame_len_bits;
75
76    /* determine frame length */
77    if (avctx->sample_rate < 22050) {
78        frame_len_bits = 9;
79    } else if (avctx->sample_rate < 44100) {
80        frame_len_bits = 10;
81    } else {
82        frame_len_bits = 11;
83    }
84
85    if (avctx->channels < 1 || avctx->channels > MAX_CHANNELS) {
86        av_log(avctx, AV_LOG_ERROR, "invalid number of channels: %d\n", avctx->channels);
87        return AVERROR_INVALIDDATA;
88    }
89    avctx->channel_layout = avctx->channels == 1 ? AV_CH_LAYOUT_MONO :
90                                                   AV_CH_LAYOUT_STEREO;
91
92    s->version_b = avctx->extradata_size >= 4 && avctx->extradata[3] == 'b';
93
94    if (avctx->codec->id == AV_CODEC_ID_BINKAUDIO_RDFT) {
95        // audio is already interleaved for the RDFT format variant
96        avctx->sample_fmt = AV_SAMPLE_FMT_FLT;
97        sample_rate  *= avctx->channels;
98        s->channels = 1;
99        if (!s->version_b)
100            frame_len_bits += av_log2(avctx->channels);
101    } else {
102        s->channels = avctx->channels;
103        avctx->sample_fmt = AV_SAMPLE_FMT_FLTP;
104    }
105
106    s->frame_len     = 1 << frame_len_bits;
107    s->overlap_len   = s->frame_len / 16;
108    s->block_size    = (s->frame_len - s->overlap_len) * s->channels;
109    sample_rate_half = (sample_rate + 1) / 2;
110    if (avctx->codec->id == AV_CODEC_ID_BINKAUDIO_RDFT)
111        s->root = 2.0 / (sqrt(s->frame_len) * 32768.0);
112    else
113        s->root = s->frame_len / (sqrt(s->frame_len) * 32768.0);
114    for (i = 0; i < 96; i++) {
115        /* constant is result of 0.066399999/log10(M_E) */
116        quant_table[i] = expf(i * 0.15289164787221953823f) * s->root;
117    }
118
119    /* calculate number of bands */
120    for (s->num_bands = 1; s->num_bands < 25; s->num_bands++)
121        if (sample_rate_half <= ff_wma_critical_freqs[s->num_bands - 1])
122            break;
123
124    s->bands = av_malloc((s->num_bands + 1) * sizeof(*s->bands));
125    if (!s->bands)
126        return AVERROR(ENOMEM);
127
128    /* populate bands data */
129    s->bands[0] = 2;
130    for (i = 1; i < s->num_bands; i++)
131        s->bands[i] = (ff_wma_critical_freqs[i - 1] * s->frame_len / sample_rate_half) & ~1;
132    s->bands[s->num_bands] = s->frame_len;
133
134    s->first = 1;
135
136    if (CONFIG_BINKAUDIO_RDFT_DECODER && avctx->codec->id == AV_CODEC_ID_BINKAUDIO_RDFT)
137        ff_rdft_init(&s->trans.rdft, frame_len_bits, DFT_C2R);
138    else if (CONFIG_BINKAUDIO_DCT_DECODER)
139        ff_dct_init(&s->trans.dct, frame_len_bits, DCT_III);
140    else
141        return -1;
142
143    return 0;
144}
145
146static float get_float(GetBitContext *gb)
147{
148    int power = get_bits(gb, 5);
149    float f = ldexpf(get_bits_long(gb, 23), power - 23);
150    if (get_bits1(gb))
151        f = -f;
152    return f;
153}
154
155static const uint8_t rle_length_tab[16] = {
156    2, 3, 4, 5, 6, 8, 9, 10, 11, 12, 13, 14, 15, 16, 32, 64
157};
158
159/**
160 * Decode Bink Audio block
161 * @param[out] out Output buffer (must contain s->block_size elements)
162 * @return 0 on success, negative error code on failure
163 */
164static int decode_block(BinkAudioContext *s, float **out, int use_dct)
165{
166    int ch, i, j, k;
167    float q, quant[25];
168    int width, coeff;
169    GetBitContext *gb = &s->gb;
170
171    if (use_dct)
172        skip_bits(gb, 2);
173
174    for (ch = 0; ch < s->channels; ch++) {
175        FFTSample *coeffs = out[ch];
176
177        if (s->version_b) {
178            if (get_bits_left(gb) < 64)
179                return AVERROR_INVALIDDATA;
180            coeffs[0] = av_int2float(get_bits_long(gb, 32)) * s->root;
181            coeffs[1] = av_int2float(get_bits_long(gb, 32)) * s->root;
182        } else {
183            if (get_bits_left(gb) < 58)
184                return AVERROR_INVALIDDATA;
185            coeffs[0] = get_float(gb) * s->root;
186            coeffs[1] = get_float(gb) * s->root;
187        }
188
189        if (get_bits_left(gb) < s->num_bands * 8)
190            return AVERROR_INVALIDDATA;
191        for (i = 0; i < s->num_bands; i++) {
192            int value = get_bits(gb, 8);
193            quant[i]  = quant_table[FFMIN(value, 95)];
194        }
195
196        k = 0;
197        q = quant[0];
198
199        // parse coefficients
200        i = 2;
201        while (i < s->frame_len) {
202            if (s->version_b) {
203                j = i + 16;
204            } else {
205                int v = get_bits1(gb);
206                if (v) {
207                    v = get_bits(gb, 4);
208                    j = i + rle_length_tab[v] * 8;
209                } else {
210                    j = i + 8;
211                }
212            }
213
214            j = FFMIN(j, s->frame_len);
215
216            width = get_bits(gb, 4);
217            if (width == 0) {
218                memset(coeffs + i, 0, (j - i) * sizeof(*coeffs));
219                i = j;
220                while (s->bands[k] < i)
221                    q = quant[k++];
222            } else {
223                while (i < j) {
224                    if (s->bands[k] == i)
225                        q = quant[k++];
226                    coeff = get_bits(gb, width);
227                    if (coeff) {
228                        int v;
229                        v = get_bits1(gb);
230                        if (v)
231                            coeffs[i] = -q * coeff;
232                        else
233                            coeffs[i] =  q * coeff;
234                    } else {
235                        coeffs[i] = 0.0f;
236                    }
237                    i++;
238                }
239            }
240        }
241
242        if (CONFIG_BINKAUDIO_DCT_DECODER && use_dct) {
243            coeffs[0] /= 0.5;
244            s->trans.dct.dct_calc(&s->trans.dct,  coeffs);
245        }
246        else if (CONFIG_BINKAUDIO_RDFT_DECODER)
247            s->trans.rdft.rdft_calc(&s->trans.rdft, coeffs);
248    }
249
250    for (ch = 0; ch < s->channels; ch++) {
251        int j;
252        int count = s->overlap_len * s->channels;
253        if (!s->first) {
254            j = ch;
255            for (i = 0; i < s->overlap_len; i++, j += s->channels)
256                out[ch][i] = (s->previous[ch][i] * (count - j) +
257                                      out[ch][i] *          j) / count;
258        }
259        memcpy(s->previous[ch], &out[ch][s->frame_len - s->overlap_len],
260               s->overlap_len * sizeof(*s->previous[ch]));
261    }
262
263    s->first = 0;
264
265    return 0;
266}
267
268static av_cold int decode_end(AVCodecContext *avctx)
269{
270    BinkAudioContext * s = avctx->priv_data;
271    av_freep(&s->bands);
272    av_freep(&s->packet_buffer);
273    if (CONFIG_BINKAUDIO_RDFT_DECODER && avctx->codec->id == AV_CODEC_ID_BINKAUDIO_RDFT)
274        ff_rdft_end(&s->trans.rdft);
275    else if (CONFIG_BINKAUDIO_DCT_DECODER)
276        ff_dct_end(&s->trans.dct);
277
278    return 0;
279}
280
281static void get_bits_align32(GetBitContext *s)
282{
283    int n = (-get_bits_count(s)) & 31;
284    if (n) skip_bits(s, n);
285}
286
287static int decode_frame(AVCodecContext *avctx, void *data,
288                        int *got_frame_ptr, AVPacket *avpkt)
289{
290    BinkAudioContext *s = avctx->priv_data;
291    AVFrame *frame      = data;
292    GetBitContext *gb = &s->gb;
293    int ret, consumed = 0;
294
295    if (!get_bits_left(gb)) {
296        uint8_t *buf;
297        /* handle end-of-stream */
298        if (!avpkt->size) {
299            *got_frame_ptr = 0;
300            return 0;
301        }
302        if (avpkt->size < 4) {
303            av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
304            return AVERROR_INVALIDDATA;
305        }
306        buf = av_realloc(s->packet_buffer, avpkt->size + FF_INPUT_BUFFER_PADDING_SIZE);
307        if (!buf)
308            return AVERROR(ENOMEM);
309        memset(buf + avpkt->size, 0, FF_INPUT_BUFFER_PADDING_SIZE);
310        s->packet_buffer = buf;
311        memcpy(s->packet_buffer, avpkt->data, avpkt->size);
312        if ((ret = init_get_bits8(gb, s->packet_buffer, avpkt->size)) < 0)
313            return ret;
314        consumed = avpkt->size;
315
316        /* skip reported size */
317        skip_bits_long(gb, 32);
318    }
319
320    /* get output buffer */
321    frame->nb_samples = s->frame_len;
322    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
323        return ret;
324
325    if (decode_block(s, (float **)frame->extended_data,
326                     avctx->codec->id == AV_CODEC_ID_BINKAUDIO_DCT)) {
327        av_log(avctx, AV_LOG_ERROR, "Incomplete packet\n");
328        return AVERROR_INVALIDDATA;
329    }
330    get_bits_align32(gb);
331
332    frame->nb_samples = s->block_size / avctx->channels;
333    *got_frame_ptr    = 1;
334
335    return consumed;
336}
337
338AVCodec ff_binkaudio_rdft_decoder = {
339    .name           = "binkaudio_rdft",
340    .long_name      = NULL_IF_CONFIG_SMALL("Bink Audio (RDFT)"),
341    .type           = AVMEDIA_TYPE_AUDIO,
342    .id             = AV_CODEC_ID_BINKAUDIO_RDFT,
343    .priv_data_size = sizeof(BinkAudioContext),
344    .init           = decode_init,
345    .close          = decode_end,
346    .decode         = decode_frame,
347    .capabilities   = CODEC_CAP_DELAY | CODEC_CAP_DR1,
348};
349
350AVCodec ff_binkaudio_dct_decoder = {
351    .name           = "binkaudio_dct",
352    .long_name      = NULL_IF_CONFIG_SMALL("Bink Audio (DCT)"),
353    .type           = AVMEDIA_TYPE_AUDIO,
354    .id             = AV_CODEC_ID_BINKAUDIO_DCT,
355    .priv_data_size = sizeof(BinkAudioContext),
356    .init           = decode_init,
357    .close          = decode_end,
358    .decode         = decode_frame,
359    .capabilities   = CODEC_CAP_DELAY | CODEC_CAP_DR1,
360};
361