FFmpeg coverage

GCC Code Coverage Report

Directory:	../../../ffmpeg/		Exec	Total	Coverage
File:	src/libavcodec/dstdec.c	Lines:	122	173	70.5 %
Date:	2020-09-25 23:16:12	Branches:	52	96	54.2 %


/*
 * Direct Stream Transfer (DST) decoder
 * Copyright (c) 2014 Peter Ross <pross@xvid.org>
 *
 * 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
 */

/**
 * @file
 * Direct Stream Transfer (DST) decoder
 * ISO/IEC 14496-3 Part 3 Subpart 10: Technical description of lossless coding of oversampled audio
 */

#include "libavutil/avassert.h"
#include "libavutil/intreadwrite.h"
#include "internal.h"
#include "get_bits.h"
#include "avcodec.h"
#include "golomb.h"
#include "mathops.h"
#include "dsd.h"

#define DST_MAX_CHANNELS 6
#define DST_MAX_ELEMENTS (2 * DST_MAX_CHANNELS)

#define DSD_FS44(sample_rate) (sample_rate * 8LL / 44100)

#define DST_SAMPLES_PER_FRAME(sample_rate) (588 * DSD_FS44(sample_rate))

static const int8_t fsets_code_pred_coeff[3][3] = {
    {  -8 },
    { -16,  8 },
    {  -9, -5, 6 },
};

static const int8_t probs_code_pred_coeff[3][3] = {
    {  -8 },
    { -16,  8 },
    { -24, 24, -8 },
};

typedef struct ArithCoder {
    unsigned int a;
    unsigned int c;
} ArithCoder;

typedef struct Table {
    unsigned int elements;
    unsigned int length[DST_MAX_ELEMENTS];
    int coeff[DST_MAX_ELEMENTS][128];
} Table;

typedef struct DSTContext {
    AVClass *class;

    GetBitContext gb;
    ArithCoder ac;
    Table fsets, probs;
    DECLARE_ALIGNED(16, uint8_t, status)[DST_MAX_CHANNELS][16];
    DECLARE_ALIGNED(16, int16_t, filter)[DST_MAX_ELEMENTS][16][256];
    DSDContext dsdctx[DST_MAX_CHANNELS];
} DSTContext;

static av_cold int decode_init(AVCodecContext *avctx)
{
    DSTContext *s = avctx->priv_data;
    int i;

    if (avctx->channels > DST_MAX_CHANNELS) {
        avpriv_request_sample(avctx, "Channel count %d", avctx->channels);
        return AVERROR_PATCHWELCOME;
    }

    // the sample rate is only allowed to be 64,128,256 * 44100 by ISO/IEC 14496-3:2005(E)
    // We are a bit more tolerant here, but this check is needed to bound the size and duration
    if (avctx->sample_rate > 512 * 44100)
        return AVERROR_INVALIDDATA;


    if (DST_SAMPLES_PER_FRAME(avctx->sample_rate) & 7) {
        return AVERROR_PATCHWELCOME;
    }

    avctx->sample_fmt = AV_SAMPLE_FMT_FLT;

    for (i = 0; i < avctx->channels; i++)
        memset(s->dsdctx[i].buf, 0x69, sizeof(s->dsdctx[i].buf));

    ff_init_dsd_data();

    return 0;
}

static int read_map(GetBitContext *gb, Table *t, unsigned int map[DST_MAX_CHANNELS], int channels)
{
    int ch;
    t->elements = 1;
    map[0] = 0;
    if (!get_bits1(gb)) {
        for (ch = 1; ch < channels; ch++) {
            int bits = av_log2(t->elements) + 1;
            map[ch] = get_bits(gb, bits);
            if (map[ch] == t->elements) {
                t->elements++;
                if (t->elements >= DST_MAX_ELEMENTS)
                    return AVERROR_INVALIDDATA;
            } else if (map[ch] > t->elements) {
                return AVERROR_INVALIDDATA;
            }
        }
    } else {
        memset(map, 0, sizeof(*map) * DST_MAX_CHANNELS);
    }
    return 0;
}

static av_always_inline int get_sr_golomb_dst(GetBitContext *gb, unsigned int k)
{
    int v = get_ur_golomb_jpegls(gb, k, get_bits_left(gb), 0);
    if (v && get_bits1(gb))
        v = -v;
    return v;
}

static void read_uncoded_coeff(GetBitContext *gb, int *dst, unsigned int elements,
                               int coeff_bits, int is_signed, int offset)
{
    int i;

    for (i = 0; i < elements; i++) {
        dst[i] = (is_signed ? get_sbits(gb, coeff_bits) : get_bits(gb, coeff_bits)) + offset;
    }
}

static int read_table(GetBitContext *gb, Table *t, const int8_t code_pred_coeff[3][3],
                      int length_bits, int coeff_bits, int is_signed, int offset)
{
    unsigned int i, j, k;
    for (i = 0; i < t->elements; i++) {
        t->length[i] = get_bits(gb, length_bits) + 1;
        if (!get_bits1(gb)) {
            read_uncoded_coeff(gb, t->coeff[i], t->length[i], coeff_bits, is_signed, offset);
        } else {
            int method = get_bits(gb, 2), lsb_size;
            if (method == 3)
                return AVERROR_INVALIDDATA;

            read_uncoded_coeff(gb, t->coeff[i], method + 1, coeff_bits, is_signed, offset);

            lsb_size  = get_bits(gb, 3);
            for (j = method + 1; j < t->length[i]; j++) {
                int c, x = 0;
                for (k = 0; k < method + 1; k++)
                    x += code_pred_coeff[method][k] * (unsigned)t->coeff[i][j - k - 1];
                c = get_sr_golomb_dst(gb, lsb_size);
                if (x >= 0)
                    c -= (x + 4) / 8;
                else
                    c += (-x + 3) / 8;
                if (!is_signed) {
                    if (c < offset || c >= offset + (1<<coeff_bits))
                        return AVERROR_INVALIDDATA;
                }
                t->coeff[i][j] = c;
            }
        }
    }
    return 0;
}

static void ac_init(ArithCoder *ac, GetBitContext *gb)
{
    ac->a = 4095;
    ac->c = get_bits(gb, 12);
}

static av_always_inline void ac_get(ArithCoder *ac, GetBitContext *gb, int p, int *e)
{
    unsigned int k = (ac->a >> 8) | ((ac->a >> 7) & 1);
    unsigned int q = k * p;
    unsigned int a_q = ac->a - q;

    *e = ac->c < a_q;
    if (*e) {
        ac->a  = a_q;
    } else {
        ac->a  = q;
        ac->c -= a_q;
    }

    if (ac->a < 2048) {
        int n = 11 - av_log2(ac->a);
        ac->a <<= n;
        ac->c = (ac->c << n) | get_bits(gb, n);
    }
}

static uint8_t prob_dst_x_bit(int c)
{
    return (ff_reverse[c & 127] >> 1) + 1;
}

static void build_filter(int16_t table[DST_MAX_ELEMENTS][16][256], const Table *fsets)
{
    int i, j, k, l;

    for (i = 0; i < fsets->elements; i++) {
        int length = fsets->length[i];

        for (j = 0; j < 16; j++) {
            int total = av_clip(length - j * 8, 0, 8);

            for (k = 0; k < 256; k++) {
                int v = 0;

                for (l = 0; l < total; l++)
                    v += (((k >> l) & 1) * 2 - 1) * fsets->coeff[i][j * 8 + l];
                table[i][j][k] = v;
            }
        }
    }
}

static int decode_frame(AVCodecContext *avctx, void *data,
                        int *got_frame_ptr, AVPacket *avpkt)
{
    unsigned samples_per_frame = DST_SAMPLES_PER_FRAME(avctx->sample_rate);
    unsigned map_ch_to_felem[DST_MAX_CHANNELS];
    unsigned map_ch_to_pelem[DST_MAX_CHANNELS];
    unsigned i, ch, same_map, dst_x_bit;
    unsigned half_prob[DST_MAX_CHANNELS];
    const int channels = avctx->channels;
    DSTContext *s = avctx->priv_data;
    GetBitContext *gb = &s->gb;
    ArithCoder *ac = &s->ac;
    AVFrame *frame = data;
    uint8_t *dsd;
    float *pcm;
    int ret;

    if (avpkt->size <= 1)
        return AVERROR_INVALIDDATA;

    frame->nb_samples = samples_per_frame / 8;
    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
        return ret;
    dsd = frame->data[0];
    pcm = (float *)frame->data[0];

    if ((ret = init_get_bits8(gb, avpkt->data, avpkt->size)) < 0)
        return ret;

    if (!get_bits1(gb)) {
        skip_bits1(gb);
        if (get_bits(gb, 6))
            return AVERROR_INVALIDDATA;
        memcpy(frame->data[0], avpkt->data + 1, FFMIN(avpkt->size - 1, frame->nb_samples * channels));
        goto dsd;
    }

    /* Segmentation (10.4, 10.5, 10.6) */

    if (!get_bits1(gb)) {
        avpriv_request_sample(avctx, "Not Same Segmentation");
        return AVERROR_PATCHWELCOME;
    }

    if (!get_bits1(gb)) {
        avpriv_request_sample(avctx, "Not Same Segmentation For All Channels");
        return AVERROR_PATCHWELCOME;
    }

    if (!get_bits1(gb)) {
        avpriv_request_sample(avctx, "Not End Of Channel Segmentation");
        return AVERROR_PATCHWELCOME;
    }

    /* Mapping (10.7, 10.8, 10.9) */

    same_map = get_bits1(gb);

    if ((ret = read_map(gb, &s->fsets, map_ch_to_felem, channels)) < 0)
        return ret;

    if (same_map) {
        s->probs.elements = s->fsets.elements;
        memcpy(map_ch_to_pelem, map_ch_to_felem, sizeof(map_ch_to_felem));
    } else {
        avpriv_request_sample(avctx, "Not Same Mapping");
        if ((ret = read_map(gb, &s->probs, map_ch_to_pelem, channels)) < 0)
            return ret;
    }

    /* Half Probability (10.10) */

    for (ch = 0; ch < channels; ch++)
        half_prob[ch] = get_bits1(gb);

    /* Filter Coef Sets (10.12) */

    ret = read_table(gb, &s->fsets, fsets_code_pred_coeff, 7, 9, 1, 0);
    if (ret < 0)
        return ret;

    /* Probability Tables (10.13) */

    ret = read_table(gb, &s->probs, probs_code_pred_coeff, 6, 7, 0, 1);
    if (ret < 0)
        return ret;

    /* Arithmetic Coded Data (10.11) */

    if (get_bits1(gb))
        return AVERROR_INVALIDDATA;
    ac_init(ac, gb);

    build_filter(s->filter, &s->fsets);

    memset(s->status, 0xAA, sizeof(s->status));
    memset(dsd, 0, frame->nb_samples * 4 * channels);

    ac_get(ac, gb, prob_dst_x_bit(s->fsets.coeff[0][0]), &dst_x_bit);

    for (i = 0; i < samples_per_frame; i++) {
        for (ch = 0; ch < channels; ch++) {
            const unsigned felem = map_ch_to_felem[ch];
            int16_t (*filter)[256] = s->filter[felem];
            uint8_t *status = s->status[ch];
            int prob, residual, v;

#define F(x) filter[(x)][status[(x)]]
            const int16_t predict = F( 0) + F( 1) + F( 2) + F( 3) +
                                    F( 4) + F( 5) + F( 6) + F( 7) +
                                    F( 8) + F( 9) + F(10) + F(11) +
                                    F(12) + F(13) + F(14) + F(15);
#undef F

            if (!half_prob[ch] || i >= s->fsets.length[felem]) {
                unsigned pelem = map_ch_to_pelem[ch];
                unsigned index = FFABS(predict) >> 3;
                prob = s->probs.coeff[pelem][FFMIN(index, s->probs.length[pelem] - 1)];
            } else {
                prob = 128;
            }

            ac_get(ac, gb, prob, &residual);
            v = ((predict >> 15) ^ residual) & 1;
            dsd[((i >> 3) * channels + ch) << 2] |= v << (7 - (i & 0x7 ));

            AV_WL64A(status + 8, (AV_RL64A(status + 8) << 1) | ((AV_RL64A(status) >> 63) & 1));
            AV_WL64A(status, (AV_RL64A(status) << 1) | v);
        }
    }

dsd:
    for (i = 0; i < channels; i++) {
        ff_dsd2pcm_translate(&s->dsdctx[i], frame->nb_samples, 0,
                             frame->data[0] + i * 4,
                             channels * 4, pcm + i, channels);
    }

    *got_frame_ptr = 1;

    return avpkt->size;
}

AVCodec ff_dst_decoder = {
    .name           = "dst",
    .long_name      = NULL_IF_CONFIG_SMALL("DST (Digital Stream Transfer)"),
    .type           = AVMEDIA_TYPE_AUDIO,
    .id             = AV_CODEC_ID_DST,
    .priv_data_size = sizeof(DSTContext),
    .init           = decode_init,
    .decode         = decode_frame,
    .capabilities   = AV_CODEC_CAP_DR1,
    .sample_fmts    = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLT,
                                                      AV_SAMPLE_FMT_NONE },
};


Generated by: GCOVR (Version 4.2)

Line	Branch	Exec	Source
1			/*
2			* Direct Stream Transfer (DST) decoder
3			* Copyright (c) 2014 Peter Ross <pross@xvid.org>
4			*
5			* This file is part of FFmpeg.
6			*
7			* FFmpeg is free software; you can redistribute it and/or
8			* modify it under the terms of the GNU Lesser General Public
9			* License as published by the Free Software Foundation; either
10			* version 2.1 of the License, or (at your option) any later version.
11			*
12			* FFmpeg is distributed in the hope that it will be useful,
13			* but WITHOUT ANY WARRANTY; without even the implied warranty of
14			* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15			* Lesser General Public License for more details.
16			*
17			* You should have received a copy of the GNU Lesser General Public
18			* License along with FFmpeg; if not, write to the Free Software
19			* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20			*/
21
22			/**
23			* @file
24			* Direct Stream Transfer (DST) decoder
25			* ISO/IEC 14496-3 Part 3 Subpart 10: Technical description of lossless coding of oversampled audio
26			*/
27
28			#include "libavutil/avassert.h"
29			#include "libavutil/intreadwrite.h"
30			#include "internal.h"
31			#include "get_bits.h"
32			#include "avcodec.h"
33			#include "golomb.h"
34			#include "mathops.h"
35			#include "dsd.h"
36
37			#define DST_MAX_CHANNELS 6
38			#define DST_MAX_ELEMENTS (2 * DST_MAX_CHANNELS)
39
40			#define DSD_FS44(sample_rate) (sample_rate * 8LL / 44100)
41
42			#define DST_SAMPLES_PER_FRAME(sample_rate) (588 * DSD_FS44(sample_rate))
43
44			static const int8_t fsets_code_pred_coeff[3][3] = {
45			{ -8 },
46			{ -16, 8 },
47			{ -9, -5, 6 },
48			};
49
50			static const int8_t probs_code_pred_coeff[3][3] = {
51			{ -8 },
52			{ -16, 8 },
53			{ -24, 24, -8 },
54			};
55
56			typedef struct ArithCoder {
57			unsigned int a;
58			unsigned int c;
59			} ArithCoder;
60
61			typedef struct Table {
62			unsigned int elements;
63			unsigned int length[DST_MAX_ELEMENTS];
64			int coeff[DST_MAX_ELEMENTS][128];
65			} Table;
66
67			typedef struct DSTContext {
68			AVClass *class;
69
70			GetBitContext gb;
71			ArithCoder ac;
72			Table fsets, probs;
73			DECLARE_ALIGNED(16, uint8_t, status)[DST_MAX_CHANNELS][16];
74			DECLARE_ALIGNED(16, int16_t, filter)[DST_MAX_ELEMENTS][16][256];
75			DSDContext dsdctx[DST_MAX_CHANNELS];
76			} DSTContext;
77
78		2	static av_cold int decode_init(AVCodecContext *avctx)
79			{
80		2	DSTContext *s = avctx->priv_data;
81			int i;
82
83	✗✓	2	if (avctx->channels > DST_MAX_CHANNELS) {
84			avpriv_request_sample(avctx, "Channel count %d", avctx->channels);
85			return AVERROR_PATCHWELCOME;
86			}
87
88			// the sample rate is only allowed to be 64,128,256 * 44100 by ISO/IEC 14496-3:2005(E)
89			// We are a bit more tolerant here, but this check is needed to bound the size and duration
90	✗✓	2	if (avctx->sample_rate > 512 * 44100)
91			return AVERROR_INVALIDDATA;
92
93
94	✗✓	2	if (DST_SAMPLES_PER_FRAME(avctx->sample_rate) & 7) {
95			return AVERROR_PATCHWELCOME;
96			}
97
98		2	avctx->sample_fmt = AV_SAMPLE_FMT_FLT;
99
100	✓✓	6	for (i = 0; i < avctx->channels; i++)
101		4	memset(s->dsdctx[i].buf, 0x69, sizeof(s->dsdctx[i].buf));
102
103		2	ff_init_dsd_data();
104
105		2	return 0;
106			}
107
108		10	static int read_map(GetBitContext gb, Table t, unsigned int map[DST_MAX_CHANNELS], int channels)
109			{
110			int ch;
111		10	t->elements = 1;
112		10	map[0] = 0;
113	✓✗	10	if (!get_bits1(gb)) {
114	✓✓	20	for (ch = 1; ch < channels; ch++) {
115		10	int bits = av_log2(t->elements) + 1;
116		10	map[ch] = get_bits(gb, bits);
117	✓✗	10	if (map[ch] == t->elements) {
118		10	t->elements++;
119	✗✓	10	if (t->elements >= DST_MAX_ELEMENTS)
120			return AVERROR_INVALIDDATA;
121			} else if (map[ch] > t->elements) {
122			return AVERROR_INVALIDDATA;
123			}
124			}
125			} else {
126			memset(map, 0, sizeof(map) DST_MAX_CHANNELS);
127			}
128		10	return 0;
129			}
130
131			static av_always_inline int get_sr_golomb_dst(GetBitContext *gb, unsigned int k)
132			{
133			int v = get_ur_golomb_jpegls(gb, k, get_bits_left(gb), 0);
134			if (v && get_bits1(gb))
135			v = -v;
136			return v;
137			}
138
139		40	static void read_uncoded_coeff(GetBitContext gb, int dst, unsigned int elements,
140			int coeff_bits, int is_signed, int offset)
141			{
142			int i;
143
144	✓✓	3880	for (i = 0; i < elements; i++) {
145	✓✓	3840	dst[i] = (is_signed ? get_sbits(gb, coeff_bits) : get_bits(gb, coeff_bits)) + offset;
146			}
147		40	}
148
149		20	static int read_table(GetBitContext gb, Table t, const int8_t code_pred_coeff[3][3],
150			int length_bits, int coeff_bits, int is_signed, int offset)
151			{
152			unsigned int i, j, k;
153	✓✓	60	for (i = 0; i < t->elements; i++) {
154		40	t->length[i] = get_bits(gb, length_bits) + 1;
155	✓✗	40	if (!get_bits1(gb)) {
156		40	read_uncoded_coeff(gb, t->coeff[i], t->length[i], coeff_bits, is_signed, offset);
157			} else {
158			int method = get_bits(gb, 2), lsb_size;
159			if (method == 3)
160			return AVERROR_INVALIDDATA;
161
162			read_uncoded_coeff(gb, t->coeff[i], method + 1, coeff_bits, is_signed, offset);
163
164			lsb_size = get_bits(gb, 3);
165			for (j = method + 1; j < t->length[i]; j++) {
166			int c, x = 0;
167			for (k = 0; k < method + 1; k++)
168			x += code_pred_coeff[method][k] * (unsigned)t->coeff[i][j - k - 1];
169			c = get_sr_golomb_dst(gb, lsb_size);
170			if (x >= 0)
171			c -= (x + 4) / 8;
172			else
173			c += (-x + 3) / 8;
174			if (!is_signed) {
175			if (c < offset \|\| c >= offset + (1<<coeff_bits))
176			return AVERROR_INVALIDDATA;
177			}
178			t->coeff[i][j] = c;
179			}
180			}
181			}
182		20	return 0;
183			}
184
185		10	static void ac_init(ArithCoder ac, GetBitContext gb)
186			{
187		10	ac->a = 4095;
188		10	ac->c = get_bits(gb, 12);
189		10	}
190
191		752650	static av_always_inline void ac_get(ArithCoder ac, GetBitContext gb, int p, int *e)
192			{
193		752650	unsigned int k = (ac->a >> 8) \| ((ac->a >> 7) & 1);
194		752650	unsigned int q = k * p;
195		752650	unsigned int a_q = ac->a - q;
196
197		752650	*e = ac->c < a_q;
198	✓✓	752650	if (*e) {
199		637782	ac->a = a_q;
200			} else {
201		114868	ac->a = q;
202		114868	ac->c -= a_q;
203			}
204
205	✓✓	752650	if (ac->a < 2048) {
206		247803	int n = 11 - av_log2(ac->a);
207		247803	ac->a <<= n;
208		247803	ac->c = (ac->c << n) \| get_bits(gb, n);
209			}
210		752650	}
211
212		10	static uint8_t prob_dst_x_bit(int c)
213			{
214		10	return (ff_reverse[c & 127] >> 1) + 1;
215			}
216
217		10	static void build_filter(int16_t table[DST_MAX_ELEMENTS][16][256], const Table *fsets)
218			{
219			int i, j, k, l;
220
221	✓✓	30	for (i = 0; i < fsets->elements; i++) {
222		20	int length = fsets->length[i];
223
224	✓✓	340	for (j = 0; j < 16; j++) {
225		320	int total = av_clip(length - j * 8, 0, 8);
226
227	✓✓	82240	for (k = 0; k < 256; k++) {
228		81920	int v = 0;
229
230	✓✓	737280	for (l = 0; l < total; l++)
231		655360	v += (((k >> l) & 1) * 2 - 1) * fsets->coeff[i][j * 8 + l];
232		81920	table[i][j][k] = v;
233			}
234			}
235			}
236		10	}
237
238		10	static int decode_frame(AVCodecContext avctx, void data,
239			int got_frame_ptr, AVPacket avpkt)
240			{
241		10	unsigned samples_per_frame = DST_SAMPLES_PER_FRAME(avctx->sample_rate);
242			unsigned map_ch_to_felem[DST_MAX_CHANNELS];
243			unsigned map_ch_to_pelem[DST_MAX_CHANNELS];
244			unsigned i, ch, same_map, dst_x_bit;
245			unsigned half_prob[DST_MAX_CHANNELS];
246		10	const int channels = avctx->channels;
247		10	DSTContext *s = avctx->priv_data;
248		10	GetBitContext *gb = &s->gb;
249		10	ArithCoder *ac = &s->ac;
250		10	AVFrame *frame = data;
251			uint8_t *dsd;
252			float *pcm;
253			int ret;
254
255	✗✓	10	if (avpkt->size <= 1)
256			return AVERROR_INVALIDDATA;
257
258		10	frame->nb_samples = samples_per_frame / 8;
259	✗✓	10	if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
260			return ret;
261		10	dsd = frame->data[0];
262		10	pcm = (float *)frame->data[0];
263
264	✗✓	10	if ((ret = init_get_bits8(gb, avpkt->data, avpkt->size)) < 0)
265			return ret;
266
267	✗✓	10	if (!get_bits1(gb)) {
268			skip_bits1(gb);
269			if (get_bits(gb, 6))
270			return AVERROR_INVALIDDATA;
271			memcpy(frame->data[0], avpkt->data + 1, FFMIN(avpkt->size - 1, frame->nb_samples * channels));
272			goto dsd;
273			}
274
275			/* Segmentation (10.4, 10.5, 10.6) */
276
277	✗✓	10	if (!get_bits1(gb)) {
278			avpriv_request_sample(avctx, "Not Same Segmentation");
279			return AVERROR_PATCHWELCOME;
280			}
281
282	✗✓	10	if (!get_bits1(gb)) {
283			avpriv_request_sample(avctx, "Not Same Segmentation For All Channels");
284			return AVERROR_PATCHWELCOME;
285			}
286
287	✗✓	10	if (!get_bits1(gb)) {
288			avpriv_request_sample(avctx, "Not End Of Channel Segmentation");
289			return AVERROR_PATCHWELCOME;
290			}
291
292			/* Mapping (10.7, 10.8, 10.9) */
293
294		10	same_map = get_bits1(gb);
295
296	✗✓	10	if ((ret = read_map(gb, &s->fsets, map_ch_to_felem, channels)) < 0)
297			return ret;
298
299	✓✗	10	if (same_map) {
300		10	s->probs.elements = s->fsets.elements;
301		10	memcpy(map_ch_to_pelem, map_ch_to_felem, sizeof(map_ch_to_felem));
302			} else {
303			avpriv_request_sample(avctx, "Not Same Mapping");
304			if ((ret = read_map(gb, &s->probs, map_ch_to_pelem, channels)) < 0)
305			return ret;
306			}
307
308			/* Half Probability (10.10) */
309
310	✓✓	30	for (ch = 0; ch < channels; ch++)
311		20	half_prob[ch] = get_bits1(gb);
312
313			/* Filter Coef Sets (10.12) */
314
315		10	ret = read_table(gb, &s->fsets, fsets_code_pred_coeff, 7, 9, 1, 0);
316	✗✓	10	if (ret < 0)
317			return ret;
318
319			/* Probability Tables (10.13) */
320
321		10	ret = read_table(gb, &s->probs, probs_code_pred_coeff, 6, 7, 0, 1);
322	✗✓	10	if (ret < 0)
323			return ret;
324
325			/* Arithmetic Coded Data (10.11) */
326
327	✗✓	10	if (get_bits1(gb))
328			return AVERROR_INVALIDDATA;
329		10	ac_init(ac, gb);
330
331		10	build_filter(s->filter, &s->fsets);
332
333		10	memset(s->status, 0xAA, sizeof(s->status));
334		10	memset(dsd, 0, frame->nb_samples * 4 * channels);
335
336		10	ac_get(ac, gb, prob_dst_x_bit(s->fsets.coeff[0][0]), &dst_x_bit);
337
338	✓✓	376330	for (i = 0; i < samples_per_frame; i++) {
339	✓✓	1128960	for (ch = 0; ch < channels; ch++) {
340		752640	const unsigned felem = map_ch_to_felem[ch];
341		752640	int16_t (*filter)[256] = s->filter[felem];
342		752640	uint8_t *status = s->status[ch];
343			int prob, residual, v;
344
345			#define F(x) filter[(x)][status[(x)]]
346		752640	const int16_t predict = F( 0) + F( 1) + F( 2) + F( 3) +
347		752640	F( 4) + F( 5) + F( 6) + F( 7) +
348		752640	F( 8) + F( 9) + F(10) + F(11) +
349		752640	F(12) + F(13) + F(14) + F(15);
350			#undef F
351
352	✓✗✓✓	752640	if (!half_prob[ch] \|\| i >= s->fsets.length[felem]) {
353		750080	unsigned pelem = map_ch_to_pelem[ch];
354		750080	unsigned index = FFABS(predict) >> 3;
355		750080	prob = s->probs.coeff[pelem][FFMIN(index, s->probs.length[pelem] - 1)];
356			} else {
357		2560	prob = 128;
358			}
359
360		752640	ac_get(ac, gb, prob, &residual);
361		752640	v = ((predict >> 15) ^ residual) & 1;
362		752640	dsd[((i >> 3) * channels + ch) << 2] \|= v << (7 - (i & 0x7 ));
363
364		752640	AV_WL64A(status + 8, (AV_RL64A(status + 8) << 1) \| ((AV_RL64A(status) >> 63) & 1));
365		752640	AV_WL64A(status, (AV_RL64A(status) << 1) \| v);
366			}
367			}
368
369		10	dsd:
370	✓✓	30	for (i = 0; i < channels; i++) {
371		20	ff_dsd2pcm_translate(&s->dsdctx[i], frame->nb_samples, 0,
372		20	frame->data[0] + i * 4,
373		20	channels * 4, pcm + i, channels);
374			}
375
376		10	*got_frame_ptr = 1;
377
378		10	return avpkt->size;
379			}
380
381			AVCodec ff_dst_decoder = {
382			.name = "dst",
383			.long_name = NULL_IF_CONFIG_SMALL("DST (Digital Stream Transfer)"),
384			.type = AVMEDIA_TYPE_AUDIO,
385			.id = AV_CODEC_ID_DST,
386			.priv_data_size = sizeof(DSTContext),
387			.init = decode_init,
388			.decode = decode_frame,
389			.capabilities = AV_CODEC_CAP_DR1,
390			.sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLT,
391			AV_SAMPLE_FMT_NONE },
392			};