summaryrefslogtreecommitdiff
path: root/libavcodec/s302menc.c (plain)
blob: b04a54e48292c82ea0742c40cb2e7367c777231a
1/*
2 * SMPTE 302M encoder
3 * Copyright (c) 2010 Google, Inc.
4 * Copyright (c) 2013 Darryl Wallace <wallacdj@gmail.com>
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#include "avcodec.h"
24#include "internal.h"
25#include "mathops.h"
26#include "put_bits.h"
27
28#define AES3_HEADER_LEN 4
29
30typedef struct S302MEncContext {
31 uint8_t framing_index; /* Set for even channels on multiple of 192 samples */
32} S302MEncContext;
33
34static av_cold int s302m_encode_init(AVCodecContext *avctx)
35{
36 S302MEncContext *s = avctx->priv_data;
37
38 if (avctx->channels & 1 || avctx->channels > 8) {
39 av_log(avctx, AV_LOG_ERROR,
40 "Encoding %d channel(s) is not allowed. Only 2, 4, 6 and 8 channels are supported.\n",
41 avctx->channels);
42 return AVERROR(EINVAL);
43 }
44
45 switch (avctx->sample_fmt) {
46 case AV_SAMPLE_FMT_S16:
47 avctx->bits_per_raw_sample = 16;
48 break;
49 case AV_SAMPLE_FMT_S32:
50 if (avctx->bits_per_raw_sample > 20) {
51 if (avctx->bits_per_raw_sample > 24)
52 av_log(avctx, AV_LOG_WARNING, "encoding as 24 bits-per-sample\n");
53 avctx->bits_per_raw_sample = 24;
54 } else if (!avctx->bits_per_raw_sample) {
55 avctx->bits_per_raw_sample = 24;
56 } else if (avctx->bits_per_raw_sample <= 20) {
57 avctx->bits_per_raw_sample = 20;
58 }
59 }
60
61 avctx->frame_size = 0;
62 avctx->bit_rate = 48000 * avctx->channels *
63 (avctx->bits_per_raw_sample + 4);
64 s->framing_index = 0;
65
66 return 0;
67}
68
69static int s302m_encode2_frame(AVCodecContext *avctx, AVPacket *avpkt,
70 const AVFrame *frame, int *got_packet_ptr)
71{
72 S302MEncContext *s = avctx->priv_data;
73 const int buf_size = AES3_HEADER_LEN +
74 (frame->nb_samples *
75 avctx->channels *
76 (avctx->bits_per_raw_sample + 4)) / 8;
77 int ret, c, channels;
78 uint8_t *o;
79 PutBitContext pb;
80
81 if (buf_size - AES3_HEADER_LEN > UINT16_MAX) {
82 av_log(avctx, AV_LOG_ERROR, "number of samples in frame too big\n");
83 return AVERROR(EINVAL);
84 }
85
86 if ((ret = ff_alloc_packet2(avctx, avpkt, buf_size, 0)) < 0)
87 return ret;
88
89 o = avpkt->data;
90 init_put_bits(&pb, o, buf_size);
91 put_bits(&pb, 16, buf_size - AES3_HEADER_LEN);
92 put_bits(&pb, 2, (avctx->channels - 2) >> 1); // number of channels
93 put_bits(&pb, 8, 0); // channel ID
94 put_bits(&pb, 2, (avctx->bits_per_raw_sample - 16) / 4); // bits per samples (0 = 16bit, 1 = 20bit, 2 = 24bit)
95 put_bits(&pb, 4, 0); // alignments
96 flush_put_bits(&pb);
97 o += AES3_HEADER_LEN;
98
99 if (avctx->bits_per_raw_sample == 24) {
100 const uint32_t *samples = (uint32_t *)frame->data[0];
101
102 for (c = 0; c < frame->nb_samples; c++) {
103 uint8_t vucf = s->framing_index == 0 ? 0x10: 0;
104
105 for (channels = 0; channels < avctx->channels; channels += 2) {
106 o[0] = ff_reverse[(samples[0] & 0x0000FF00) >> 8];
107 o[1] = ff_reverse[(samples[0] & 0x00FF0000) >> 16];
108 o[2] = ff_reverse[(samples[0] & 0xFF000000) >> 24];
109 o[3] = ff_reverse[(samples[1] & 0x00000F00) >> 4] | vucf;
110 o[4] = ff_reverse[(samples[1] & 0x000FF000) >> 12];
111 o[5] = ff_reverse[(samples[1] & 0x0FF00000) >> 20];
112 o[6] = ff_reverse[(samples[1] & 0xF0000000) >> 28];
113 o += 7;
114 samples += 2;
115 }
116
117 s->framing_index++;
118 if (s->framing_index >= 192)
119 s->framing_index = 0;
120 }
121 } else if (avctx->bits_per_raw_sample == 20) {
122 const uint32_t *samples = (uint32_t *)frame->data[0];
123
124 for (c = 0; c < frame->nb_samples; c++) {
125 uint8_t vucf = s->framing_index == 0 ? 0x80: 0;
126
127 for (channels = 0; channels < avctx->channels; channels += 2) {
128 o[0] = ff_reverse[ (samples[0] & 0x000FF000) >> 12];
129 o[1] = ff_reverse[ (samples[0] & 0x0FF00000) >> 20];
130 o[2] = ff_reverse[((samples[0] & 0xF0000000) >> 28) | vucf];
131 o[3] = ff_reverse[ (samples[1] & 0x000FF000) >> 12];
132 o[4] = ff_reverse[ (samples[1] & 0x0FF00000) >> 20];
133 o[5] = ff_reverse[ (samples[1] & 0xF0000000) >> 28];
134 o += 6;
135 samples += 2;
136 }
137
138 s->framing_index++;
139 if (s->framing_index >= 192)
140 s->framing_index = 0;
141 }
142 } else if (avctx->bits_per_raw_sample == 16) {
143 const uint16_t *samples = (uint16_t *)frame->data[0];
144
145 for (c = 0; c < frame->nb_samples; c++) {
146 uint8_t vucf = s->framing_index == 0 ? 0x10 : 0;
147
148 for (channels = 0; channels < avctx->channels; channels += 2) {
149 o[0] = ff_reverse[ samples[0] & 0xFF];
150 o[1] = ff_reverse[(samples[0] & 0xFF00) >> 8];
151 o[2] = ff_reverse[(samples[1] & 0x0F) << 4] | vucf;
152 o[3] = ff_reverse[(samples[1] & 0x0FF0) >> 4];
153 o[4] = ff_reverse[(samples[1] & 0xF000) >> 12];
154 o += 5;
155 samples += 2;
156
157 }
158
159 s->framing_index++;
160 if (s->framing_index >= 192)
161 s->framing_index = 0;
162 }
163 }
164
165 *got_packet_ptr = 1;
166
167 return 0;
168}
169
170AVCodec ff_s302m_encoder = {
171 .name = "s302m",
172 .long_name = NULL_IF_CONFIG_SMALL("SMPTE 302M"),
173 .type = AVMEDIA_TYPE_AUDIO,
174 .id = AV_CODEC_ID_S302M,
175 .priv_data_size = sizeof(S302MEncContext),
176 .init = s302m_encode_init,
177 .encode2 = s302m_encode2_frame,
178 .sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S32,
179 AV_SAMPLE_FMT_S16,
180 AV_SAMPLE_FMT_NONE },
181 .capabilities = AV_CODEC_CAP_VARIABLE_FRAME_SIZE | AV_CODEC_CAP_EXPERIMENTAL,
182 .supported_samplerates = (const int[]) { 48000, 0 },
183 /* .channel_layouts = (const uint64_t[]) { AV_CH_LAYOUT_STEREO,
184 AV_CH_LAYOUT_QUAD,
185 AV_CH_LAYOUT_5POINT1_BACK,
186 AV_CH_LAYOUT_5POINT1_BACK | AV_CH_LAYOUT_STEREO_DOWNMIX,
187 0 }, */
188};
189
generated by cgit at 2024-05-17 05:49:57 (GMT)