/src/ffmpeg/libavcodec/sbcenc.c

Source
/*
 * Bluetooth low-complexity, subband codec (SBC)
 *
 * Copyright (C) 2017  Aurelien Jacobs <aurel@gnuage.org>
 * Copyright (C) 2012-2013  Intel Corporation
 * Copyright (C) 2008-2010  Nokia Corporation
 * Copyright (C) 2004-2010  Marcel Holtmann <marcel@holtmann.org>
 * Copyright (C) 2004-2005  Henryk Ploetz <henryk@ploetzli.ch>
 * Copyright (C) 2005-2008  Brad Midgley <bmidgley@xmission.com>
 *
 * 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
 * SBC encoder implementation
 */

#include "libavutil/channel_layout.h"
#include "libavutil/opt.h"
#include "avcodec.h"
#include "codec_internal.h"
#include "encode.h"
#include "profiles.h"
#include "put_bits.h"
#include "sbc.h"
#include "sbcdsp.h"

typedef struct SBCEncContext {
    AVClass *class;
    int64_t max_delay;
    int msbc;
    DECLARE_ALIGNED(SBC_ALIGN, struct sbc_frame, frame);
    DECLARE_ALIGNED(SBC_ALIGN, SBCDSPContext, dsp);
} SBCEncContext;

static const int sbc_samplerates[] = { 16000, 32000, 44100, 48000, 0 };

static int sbc_analyze_audio(SBCDSPContext *s, struct sbc_frame *frame)
{
    int ch, blk;
    int16_t *x;

    switch (frame->subbands) {
    case 4:
        for (ch = 0; ch < frame->channels; ch++) {
            x = &s->X[ch][s->position - 4 *
                    s->increment + frame->blocks * 4];
            for (blk = 0; blk < frame->blocks;
                        blk += s->increment) {
                s->sbc_analyze_4s(
                    s, x,
                    frame->sb_sample_f[blk][ch],
                    frame->sb_sample_f[blk + 1][ch] -
                    frame->sb_sample_f[blk][ch]);
                x -= 4 * s->increment;
            }
        }
        return frame->blocks * 4;

    case 8:
        for (ch = 0; ch < frame->channels; ch++) {
            x = &s->X[ch][s->position - 8 *
                    s->increment + frame->blocks * 8];
            for (blk = 0; blk < frame->blocks;
                        blk += s->increment) {
                s->sbc_analyze_8s(
                    s, x,
                    frame->sb_sample_f[blk][ch],
                    frame->sb_sample_f[blk + 1][ch] -
                    frame->sb_sample_f[blk][ch]);
                x -= 8 * s->increment;
            }
        }
        return frame->blocks * 8;

    default:
        return AVERROR(EIO);
    }
}

/*
 * Packs the SBC frame from frame into the memory in avpkt.
 * Returns the length of the packed frame.
 */
static size_t sbc_pack_frame(AVPacket *avpkt, struct sbc_frame *frame,
                             int joint, int msbc)
{
    PutBitContext pb;

    /* Will copy the header parts for CRC-8 calculation here */
    uint8_t crc_header[11] = { 0 };
    int crc_pos;

    uint32_t audio_sample;

    int ch, sb, blk;        /* channel, subband, block and bit counters */
    int bits[2][8];         /* bits distribution */
    uint32_t levels[2][8];  /* levels are derived from that */
    uint32_t sb_sample_delta[2][8];

    if (msbc) {
        avpkt->data[0] = MSBC_SYNCWORD;
        avpkt->data[1] = 0;
        avpkt->data[2] = 0;
    } else {
        avpkt->data[0] = SBC_SYNCWORD;

        avpkt->data[1]  = (frame->frequency           & 0x03) << 6;
        avpkt->data[1] |= (((frame->blocks >> 2) - 1) & 0x03) << 4;
        avpkt->data[1] |= (frame->mode                & 0x03) << 2;
        avpkt->data[1] |= (frame->allocation          & 0x01) << 1;
        avpkt->data[1] |= ((frame->subbands == 8)     & 0x01) << 0;

        avpkt->data[2] = frame->bitpool;
    }

    /* Can't fill in crc yet */
    crc_header[0] = avpkt->data[1];
    crc_header[1] = avpkt->data[2];
    crc_pos = 16;

    init_put_bits(&pb, avpkt->data + 4, avpkt->size - 4);

    if (frame->mode == JOINT_STEREO) {
        put_bits(&pb, frame->subbands, joint);
        crc_header[crc_pos >> 3] = joint;
        crc_pos += frame->subbands;
    }

    for (ch = 0; ch < frame->channels; ch++) {
        for (sb = 0; sb < frame->subbands; sb++) {
            put_bits(&pb, 4, frame->scale_factor[ch][sb] & 0x0F);
            crc_header[crc_pos >> 3] <<= 4;
            crc_header[crc_pos >> 3] |= frame->scale_factor[ch][sb] & 0x0F;
            crc_pos += 4;
        }
    }

    /* align the last crc byte */
    if (crc_pos % 8)
        crc_header[crc_pos >> 3] <<= 8 - (crc_pos % 8);

    avpkt->data[3] = ff_sbc_crc8(frame->crc_ctx, crc_header, crc_pos);

    ff_sbc_calculate_bits(frame, bits);

    for (ch = 0; ch < frame->channels; ch++) {
        for (sb = 0; sb < frame->subbands; sb++) {
            levels[ch][sb] = ((1 << bits[ch][sb]) - 1) <<
                (32 - (frame->scale_factor[ch][sb] +
                    SCALE_OUT_BITS + 2));
            sb_sample_delta[ch][sb] = (uint32_t) 1 <<
                (frame->scale_factor[ch][sb] +
                    SCALE_OUT_BITS + 1);
        }
    }

    for (blk = 0; blk < frame->blocks; blk++) {
        for (ch = 0; ch < frame->channels; ch++) {
            for (sb = 0; sb < frame->subbands; sb++) {

                if (bits[ch][sb] == 0)
                    continue;

                audio_sample = ((uint64_t) levels[ch][sb] *
                    (sb_sample_delta[ch][sb] +
                    frame->sb_sample_f[blk][ch][sb])) >> 32;

                put_bits(&pb, bits[ch][sb], audio_sample);
            }
        }
    }

    flush_put_bits(&pb);

    return put_bytes_output(&pb);
}

static av_cold int sbc_encode_init(AVCodecContext *avctx)
{
    SBCEncContext *sbc = avctx->priv_data;
    struct sbc_frame *frame = &sbc->frame;

    if (avctx->profile == AV_PROFILE_SBC_MSBC)
        sbc->msbc = 1;

    if (sbc->msbc) {
        if (avctx->ch_layout.nb_channels != 1) {
            av_log(avctx, AV_LOG_ERROR, "mSBC require mono channel.\n");
            return AVERROR(EINVAL);
        }

        if (avctx->sample_rate != 16000) {
            av_log(avctx, AV_LOG_ERROR, "mSBC require 16 kHz samplerate.\n");
            return AVERROR(EINVAL);
        }

        frame->mode = SBC_MODE_MONO;
        frame->subbands = 8;
        frame->blocks = MSBC_BLOCKS;
        frame->allocation = SBC_AM_LOUDNESS;
        frame->bitpool = 26;

        avctx->frame_size = 8 * MSBC_BLOCKS;
    } else {
        int d;

        if (avctx->global_quality > 255*FF_QP2LAMBDA) {
            av_log(avctx, AV_LOG_ERROR, "bitpool > 255 is not allowed.\n");
            return AVERROR(EINVAL);
        }

        if (avctx->ch_layout.nb_channels == 1) {
            frame->mode = SBC_MODE_MONO;
            if (sbc->max_delay <= 3000 || avctx->bit_rate > 270000)
                frame->subbands = 4;
            else
                frame->subbands = 8;
        } else {
            if (avctx->bit_rate < 180000 || avctx->bit_rate > 420000)
                frame->mode = SBC_MODE_JOINT_STEREO;
            else
                frame->mode = SBC_MODE_STEREO;
            if (sbc->max_delay <= 4000 || avctx->bit_rate > 420000)
                frame->subbands = 4;
            else
                frame->subbands = 8;
        }
        /* sbc algorithmic delay is ((blocks + 10) * subbands - 2) / sample_rate */
        frame->blocks = av_clip(((sbc->max_delay * avctx->sample_rate + 2)
                               / (1000000 * frame->subbands)) - 10, 4, 16) & ~3;

        frame->allocation = SBC_AM_LOUDNESS;

        d = frame->blocks * ((frame->mode == SBC_MODE_DUAL_CHANNEL) + 1);
        frame->bitpool = (((avctx->bit_rate * frame->subbands * frame->blocks) / avctx->sample_rate)
                          - 4 * frame->subbands * avctx->ch_layout.nb_channels
                          - (frame->mode == SBC_MODE_JOINT_STEREO)*frame->subbands - 32 + d/2) / d;
        if (avctx->global_quality > 0)
            frame->bitpool = avctx->global_quality / FF_QP2LAMBDA;

        if (frame->bitpool > frame->subbands << (4 + (frame->mode == STEREO
                                                   || frame->mode == JOINT_STEREO))) {
            av_log(avctx, AV_LOG_ERROR, "Invalid parameter combination\n");
            return AVERROR_PATCHWELCOME;
        }

        avctx->frame_size = 4*((frame->subbands >> 3) + 1) * 4*(frame->blocks >> 2);
    }

    for (int i = 0; sbc_samplerates[i]; i++)
        if (avctx->sample_rate == sbc_samplerates[i])
            frame->frequency = i;

    frame->channels = avctx->ch_layout.nb_channels;
    frame->codesize = frame->subbands * frame->blocks * avctx->ch_layout.nb_channels * 2;
    frame->crc_ctx = av_crc_get_table(AV_CRC_8_EBU);

    sbc->dsp.position = (SBC_X_BUFFER_SIZE - frame->subbands * 9) & ~7;
    sbc->dsp.increment = sbc->msbc ? 1 : 4;
    ff_sbcdsp_init(&sbc->dsp);

    return 0;
}

static int sbc_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
                            const AVFrame *av_frame, int *got_packet_ptr)
{
    SBCEncContext *sbc = avctx->priv_data;
    struct sbc_frame *frame = &sbc->frame;
    uint8_t joint = frame->mode == SBC_MODE_JOINT_STEREO;
    uint8_t dual  = frame->mode == SBC_MODE_DUAL_CHANNEL;
    int ret, j = 0;

    int frame_length = 4 + (4 * frame->subbands * frame->channels) / 8
                     + ((frame->blocks * frame->bitpool * (1 + dual)
                     + joint * frame->subbands) + 7) / 8;

    /* input must be large enough to encode a complete frame */
    if (av_frame->nb_samples * frame->channels * 2 < frame->codesize)
        return 0;

    if ((ret = ff_get_encode_buffer(avctx, avpkt, frame_length, 0)) < 0)
        return ret;

    /* Select the needed input data processing function and call it */
    if (frame->subbands == 8)
        sbc->dsp.position = sbc->dsp.sbc_enc_process_input_8s(
                sbc->dsp.position, av_frame->data[0], sbc->dsp.X,
                frame->subbands * frame->blocks, frame->channels);
    else
        sbc->dsp.position = sbc->dsp.sbc_enc_process_input_4s(
                sbc->dsp.position, av_frame->data[0], sbc->dsp.X,
                frame->subbands * frame->blocks, frame->channels);

    sbc_analyze_audio(&sbc->dsp, &sbc->frame);

    if (frame->mode == JOINT_STEREO)
        j = sbc->dsp.sbc_calc_scalefactors_j(frame->sb_sample_f,
                                             frame->scale_factor,
                                             frame->blocks,
                                             frame->subbands);
    else
        sbc->dsp.sbc_calc_scalefactors(frame->sb_sample_f,
                                       frame->scale_factor,
                                       frame->blocks,
                                       frame->channels,
                                       frame->subbands);
    sbc_pack_frame(avpkt, frame, j, sbc->msbc);

    *got_packet_ptr = 1;
    return 0;
}

#define OFFSET(x) offsetof(SBCEncContext, x)
#define AE AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_ENCODING_PARAM
static const AVOption options[] = {
    { "sbc_delay", "set maximum algorithmic latency",
      OFFSET(max_delay), AV_OPT_TYPE_DURATION, {.i64 = 13000}, 1000,13000, AE },
    { "msbc",      "use mSBC mode (wideband speech mono SBC)",
      OFFSET(msbc),      AV_OPT_TYPE_BOOL,     {.i64 = 0},        0,    1, AE },
    FF_AVCTX_PROFILE_OPTION("msbc", NULL, AUDIO, AV_PROFILE_SBC_MSBC)
    { NULL },
};

static const AVClass sbc_class = {
    .class_name = "sbc encoder",
    .item_name  = av_default_item_name,
    .option     = options,
    .version    = LIBAVUTIL_VERSION_INT,
};

const FFCodec ff_sbc_encoder = {
    .p.name                = "sbc",
    CODEC_LONG_NAME("SBC (low-complexity subband codec)"),
    .p.type                = AVMEDIA_TYPE_AUDIO,
    .p.id                  = AV_CODEC_ID_SBC,
    .p.capabilities        = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_SMALL_LAST_FRAME |
                             AV_CODEC_CAP_ENCODER_REORDERED_OPAQUE,
    .priv_data_size        = sizeof(SBCEncContext),
    .init                  = sbc_encode_init,
    FF_CODEC_ENCODE_CB(sbc_encode_frame),
    CODEC_CH_LAYOUTS(AV_CHANNEL_LAYOUT_MONO, AV_CHANNEL_LAYOUT_STEREO),
    CODEC_SAMPLEFMTS(AV_SAMPLE_FMT_S16),
    CODEC_SAMPLERATES_ARRAY(sbc_samplerates),
    .p.priv_class          = &sbc_class,
    .p.profiles            = NULL_IF_CONFIG_SMALL(ff_sbc_profiles),
};

Coverage Report

Created: 2026-05-23 07:06

Line	Count	Source
1		/*
2		* Bluetooth low-complexity, subband codec (SBC)
3		*
4		* Copyright (C) 2017 Aurelien Jacobs <aurel@gnuage.org>
5		* Copyright (C) 2012-2013 Intel Corporation
6		* Copyright (C) 2008-2010 Nokia Corporation
7		* Copyright (C) 2004-2010 Marcel Holtmann <marcel@holtmann.org>
8		* Copyright (C) 2004-2005 Henryk Ploetz <henryk@ploetzli.ch>
9		* Copyright (C) 2005-2008 Brad Midgley <bmidgley@xmission.com>
10		*
11		* This file is part of FFmpeg.
12		*
13		* FFmpeg is free software; you can redistribute it and/or
14		* modify it under the terms of the GNU Lesser General Public
15		* License as published by the Free Software Foundation; either
16		* version 2.1 of the License, or (at your option) any later version.
17		*
18		* FFmpeg is distributed in the hope that it will be useful,
19		* but WITHOUT ANY WARRANTY; without even the implied warranty of
20		* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
21		* Lesser General Public License for more details.
22		*
23		* You should have received a copy of the GNU Lesser General Public
24		* License along with FFmpeg; if not, write to the Free Software
25		* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
26		*/
27
28		/**
29		* @file
30		* SBC encoder implementation
31		*/
32
33		#include "libavutil/channel_layout.h"
34		#include "libavutil/opt.h"
35		#include "avcodec.h"
36		#include "codec_internal.h"
37		#include "encode.h"
38		#include "profiles.h"
39		#include "put_bits.h"
40		#include "sbc.h"
41		#include "sbcdsp.h"
42
43		typedef struct SBCEncContext {
44		AVClass *class;
45		int64_t max_delay;
46		int msbc;
47		DECLARE_ALIGNED(SBC_ALIGN, struct sbc_frame, frame);
48		DECLARE_ALIGNED(SBC_ALIGN, SBCDSPContext, dsp);
49		} SBCEncContext;
50
51		static const int sbc_samplerates[] = { 16000, 32000, 44100, 48000, 0 };
52
53		static int sbc_analyze_audio(SBCDSPContext s, struct sbc_frame frame)
54	0	{
55	0	int ch, blk;
56	0	int16_t *x;
57
58	0	switch (frame->subbands) {
59	0	case 4:
60	0	for (ch = 0; ch < frame->channels; ch++) {
61	0	x = &s->X[ch][s->position - 4 *
62	0	s->increment + frame->blocks * 4];
63	0	for (blk = 0; blk < frame->blocks;
64	0	blk += s->increment) {
65	0	s->sbc_analyze_4s(
66	0	s, x,
67	0	frame->sb_sample_f[blk][ch],
68	0	frame->sb_sample_f[blk + 1][ch] -
69	0	frame->sb_sample_f[blk][ch]);
70	0	x -= 4 * s->increment;
71	0	}
72	0	}
73	0	return frame->blocks * 4;
74
75	0	case 8:
76	0	for (ch = 0; ch < frame->channels; ch++) {
77	0	x = &s->X[ch][s->position - 8 *
78	0	s->increment + frame->blocks * 8];
79	0	for (blk = 0; blk < frame->blocks;
80	0	blk += s->increment) {
81	0	s->sbc_analyze_8s(
82	0	s, x,
83	0	frame->sb_sample_f[blk][ch],
84	0	frame->sb_sample_f[blk + 1][ch] -
85	0	frame->sb_sample_f[blk][ch]);
86	0	x -= 8 * s->increment;
87	0	}
88	0	}
89	0	return frame->blocks * 8;
90
91	0	default:
92	0	return AVERROR(EIO);
93	0	}
94	0	}
95
96		/*
97		* Packs the SBC frame from frame into the memory in avpkt.
98		* Returns the length of the packed frame.
99		*/
100		static size_t sbc_pack_frame(AVPacket avpkt, struct sbc_frame frame,
101		int joint, int msbc)
102	0	{
103	0	PutBitContext pb;
104
105		/* Will copy the header parts for CRC-8 calculation here */
106	0	uint8_t crc_header[11] = { 0 };
107	0	int crc_pos;
108
109	0	uint32_t audio_sample;
110
111	0	int ch, sb, blk; /* channel, subband, block and bit counters */
112	0	int bits[2][8]; /* bits distribution */
113	0	uint32_t levels[2][8]; /* levels are derived from that */
114	0	uint32_t sb_sample_delta[2][8];
115
116	0	if (msbc) {
117	0	avpkt->data[0] = MSBC_SYNCWORD;
118	0	avpkt->data[1] = 0;
119	0	avpkt->data[2] = 0;
120	0	} else {
121	0	avpkt->data[0] = SBC_SYNCWORD;
122
123	0	avpkt->data[1] = (frame->frequency & 0x03) << 6;
124	0	avpkt->data[1] \|= (((frame->blocks >> 2) - 1) & 0x03) << 4;
125	0	avpkt->data[1] \|= (frame->mode & 0x03) << 2;
126	0	avpkt->data[1] \|= (frame->allocation & 0x01) << 1;
127	0	avpkt->data[1] \|= ((frame->subbands == 8) & 0x01) << 0;
128
129	0	avpkt->data[2] = frame->bitpool;
130	0	}
131
132		/* Can't fill in crc yet */
133	0	crc_header[0] = avpkt->data[1];
134	0	crc_header[1] = avpkt->data[2];
135	0	crc_pos = 16;
136
137	0	init_put_bits(&pb, avpkt->data + 4, avpkt->size - 4);
138
139	0	if (frame->mode == JOINT_STEREO) {
140	0	put_bits(&pb, frame->subbands, joint);
141	0	crc_header[crc_pos >> 3] = joint;
142	0	crc_pos += frame->subbands;
143	0	}
144
145	0	for (ch = 0; ch < frame->channels; ch++) {
146	0	for (sb = 0; sb < frame->subbands; sb++) {
147	0	put_bits(&pb, 4, frame->scale_factor[ch][sb] & 0x0F);
148	0	crc_header[crc_pos >> 3] <<= 4;
149	0	crc_header[crc_pos >> 3] \|= frame->scale_factor[ch][sb] & 0x0F;
150	0	crc_pos += 4;
151	0	}
152	0	}
153
154		/* align the last crc byte */
155	0	if (crc_pos % 8)
156	0	crc_header[crc_pos >> 3] <<= 8 - (crc_pos % 8);
157
158	0	avpkt->data[3] = ff_sbc_crc8(frame->crc_ctx, crc_header, crc_pos);
159
160	0	ff_sbc_calculate_bits(frame, bits);
161
162	0	for (ch = 0; ch < frame->channels; ch++) {
163	0	for (sb = 0; sb < frame->subbands; sb++) {
164	0	levels[ch][sb] = ((1 << bits[ch][sb]) - 1) <<
165	0	(32 - (frame->scale_factor[ch][sb] +
166	0	SCALE_OUT_BITS + 2));
167	0	sb_sample_delta[ch][sb] = (uint32_t) 1 <<
168	0	(frame->scale_factor[ch][sb] +
169	0	SCALE_OUT_BITS + 1);
170	0	}
171	0	}
172
173	0	for (blk = 0; blk < frame->blocks; blk++) {
174	0	for (ch = 0; ch < frame->channels; ch++) {
175	0	for (sb = 0; sb < frame->subbands; sb++) {
176
177	0	if (bits[ch][sb] == 0)
178	0	continue;
179
180	0	audio_sample = ((uint64_t) levels[ch][sb] *
181	0	(sb_sample_delta[ch][sb] +
182	0	frame->sb_sample_f[blk][ch][sb])) >> 32;
183
184	0	put_bits(&pb, bits[ch][sb], audio_sample);
185	0	}
186	0	}
187	0	}
188
189	0	flush_put_bits(&pb);
190
191	0	return put_bytes_output(&pb);
192	0	}
193
194		static av_cold int sbc_encode_init(AVCodecContext *avctx)
195	0	{
196	0	SBCEncContext *sbc = avctx->priv_data;
197	0	struct sbc_frame *frame = &sbc->frame;
198
199	0	if (avctx->profile == AV_PROFILE_SBC_MSBC)
200	0	sbc->msbc = 1;
201
202	0	if (sbc->msbc) {
203	0	if (avctx->ch_layout.nb_channels != 1) {
204	0	av_log(avctx, AV_LOG_ERROR, "mSBC require mono channel.\n");
205	0	return AVERROR(EINVAL);
206	0	}
207
208	0	if (avctx->sample_rate != 16000) {
209	0	av_log(avctx, AV_LOG_ERROR, "mSBC require 16 kHz samplerate.\n");
210	0	return AVERROR(EINVAL);
211	0	}
212
213	0	frame->mode = SBC_MODE_MONO;
214	0	frame->subbands = 8;
215	0	frame->blocks = MSBC_BLOCKS;
216	0	frame->allocation = SBC_AM_LOUDNESS;
217	0	frame->bitpool = 26;
218
219	0	avctx->frame_size = 8 * MSBC_BLOCKS;
220	0	} else {
221	0	int d;
222
223	0	if (avctx->global_quality > 255*FF_QP2LAMBDA) {
224	0	av_log(avctx, AV_LOG_ERROR, "bitpool > 255 is not allowed.\n");
225	0	return AVERROR(EINVAL);
226	0	}
227
228	0	if (avctx->ch_layout.nb_channels == 1) {
229	0	frame->mode = SBC_MODE_MONO;
230	0	if (sbc->max_delay <= 3000 \|\| avctx->bit_rate > 270000)
231	0	frame->subbands = 4;
232	0	else
233	0	frame->subbands = 8;
234	0	} else {
235	0	if (avctx->bit_rate < 180000 \|\| avctx->bit_rate > 420000)
236	0	frame->mode = SBC_MODE_JOINT_STEREO;
237	0	else
238	0	frame->mode = SBC_MODE_STEREO;
239	0	if (sbc->max_delay <= 4000 \|\| avctx->bit_rate > 420000)
240	0	frame->subbands = 4;
241	0	else
242	0	frame->subbands = 8;
243	0	}
244		/* sbc algorithmic delay is ((blocks + 10) * subbands - 2) / sample_rate */
245	0	frame->blocks = av_clip(((sbc->max_delay * avctx->sample_rate + 2)
246	0	/ (1000000 * frame->subbands)) - 10, 4, 16) & ~3;
247
248	0	frame->allocation = SBC_AM_LOUDNESS;
249
250	0	d = frame->blocks * ((frame->mode == SBC_MODE_DUAL_CHANNEL) + 1);
251	0	frame->bitpool = (((avctx->bit_rate * frame->subbands * frame->blocks) / avctx->sample_rate)
252	0	- 4 * frame->subbands * avctx->ch_layout.nb_channels
253	0	- (frame->mode == SBC_MODE_JOINT_STEREO)*frame->subbands - 32 + d/2) / d;
254	0	if (avctx->global_quality > 0)
255	0	frame->bitpool = avctx->global_quality / FF_QP2LAMBDA;
256
257	0	if (frame->bitpool > frame->subbands << (4 + (frame->mode == STEREO
258	0	\|\| frame->mode == JOINT_STEREO))) {
259	0	av_log(avctx, AV_LOG_ERROR, "Invalid parameter combination\n");
260	0	return AVERROR_PATCHWELCOME;
261	0	}
262
263	0	avctx->frame_size = 4((frame->subbands >> 3) + 1) 4*(frame->blocks >> 2);
264	0	}
265
266	0	for (int i = 0; sbc_samplerates[i]; i++)
267	0	if (avctx->sample_rate == sbc_samplerates[i])
268	0	frame->frequency = i;
269
270	0	frame->channels = avctx->ch_layout.nb_channels;
271	0	frame->codesize = frame->subbands * frame->blocks * avctx->ch_layout.nb_channels * 2;
272	0	frame->crc_ctx = av_crc_get_table(AV_CRC_8_EBU);
273
274	0	sbc->dsp.position = (SBC_X_BUFFER_SIZE - frame->subbands * 9) & ~7;
275	0	sbc->dsp.increment = sbc->msbc ? 1 : 4;
276	0	ff_sbcdsp_init(&sbc->dsp);
277
278	0	return 0;
279	0	}
280
281		static int sbc_encode_frame(AVCodecContext avctx, AVPacket avpkt,
282		const AVFrame av_frame, int got_packet_ptr)
283	0	{
284	0	SBCEncContext *sbc = avctx->priv_data;
285	0	struct sbc_frame *frame = &sbc->frame;
286	0	uint8_t joint = frame->mode == SBC_MODE_JOINT_STEREO;
287	0	uint8_t dual = frame->mode == SBC_MODE_DUAL_CHANNEL;
288	0	int ret, j = 0;
289
290	0	int frame_length = 4 + (4 * frame->subbands * frame->channels) / 8
291	0	+ ((frame->blocks * frame->bitpool * (1 + dual)
292	0	+ joint * frame->subbands) + 7) / 8;
293
294		/* input must be large enough to encode a complete frame */
295	0	if (av_frame->nb_samples * frame->channels * 2 < frame->codesize)
296	0	return 0;
297
298	0	if ((ret = ff_get_encode_buffer(avctx, avpkt, frame_length, 0)) < 0)
299	0	return ret;
300
301		/* Select the needed input data processing function and call it */
302	0	if (frame->subbands == 8)
303	0	sbc->dsp.position = sbc->dsp.sbc_enc_process_input_8s(
304	0	sbc->dsp.position, av_frame->data[0], sbc->dsp.X,
305	0	frame->subbands * frame->blocks, frame->channels);
306	0	else
307	0	sbc->dsp.position = sbc->dsp.sbc_enc_process_input_4s(
308	0	sbc->dsp.position, av_frame->data[0], sbc->dsp.X,
309	0	frame->subbands * frame->blocks, frame->channels);
310
311	0	sbc_analyze_audio(&sbc->dsp, &sbc->frame);
312
313	0	if (frame->mode == JOINT_STEREO)
314	0	j = sbc->dsp.sbc_calc_scalefactors_j(frame->sb_sample_f,
315	0	frame->scale_factor,
316	0	frame->blocks,
317	0	frame->subbands);
318	0	else
319	0	sbc->dsp.sbc_calc_scalefactors(frame->sb_sample_f,
320	0	frame->scale_factor,
321	0	frame->blocks,
322	0	frame->channels,
323	0	frame->subbands);
324	0	sbc_pack_frame(avpkt, frame, j, sbc->msbc);
325
326	0	*got_packet_ptr = 1;
327	0	return 0;
328	0	}
329
330		#define OFFSET(x) offsetof(SBCEncContext, x)
331		#define AE AV_OPT_FLAG_AUDIO_PARAM \| AV_OPT_FLAG_ENCODING_PARAM
332		static const AVOption options[] = {
333		{ "sbc_delay", "set maximum algorithmic latency",
334		OFFSET(max_delay), AV_OPT_TYPE_DURATION, {.i64 = 13000}, 1000,13000, AE },
335		{ "msbc", "use mSBC mode (wideband speech mono SBC)",
336		OFFSET(msbc), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, AE },
337		FF_AVCTX_PROFILE_OPTION("msbc", NULL, AUDIO, AV_PROFILE_SBC_MSBC)
338		{ NULL },
339		};
340
341		static const AVClass sbc_class = {
342		.class_name = "sbc encoder",
343		.item_name = av_default_item_name,
344		.option = options,
345		.version = LIBAVUTIL_VERSION_INT,
346		};
347
348		const FFCodec ff_sbc_encoder = {
349		.p.name = "sbc",
350		CODEC_LONG_NAME("SBC (low-complexity subband codec)"),
351		.p.type = AVMEDIA_TYPE_AUDIO,
352		.p.id = AV_CODEC_ID_SBC,
353		.p.capabilities = AV_CODEC_CAP_DR1 \| AV_CODEC_CAP_SMALL_LAST_FRAME \|
354		AV_CODEC_CAP_ENCODER_REORDERED_OPAQUE,
355		.priv_data_size = sizeof(SBCEncContext),
356		.init = sbc_encode_init,
357		FF_CODEC_ENCODE_CB(sbc_encode_frame),
358		CODEC_CH_LAYOUTS(AV_CHANNEL_LAYOUT_MONO, AV_CHANNEL_LAYOUT_STEREO),
359		CODEC_SAMPLEFMTS(AV_SAMPLE_FMT_S16),
360		CODEC_SAMPLERATES_ARRAY(sbc_samplerates),
361		.p.priv_class = &sbc_class,
362		.p.profiles = NULL_IF_CONFIG_SMALL(ff_sbc_profiles),
363		};