3 * Copyright (c) 2010 Google, Inc.
4 * Copyright (c) 2013 Darryl Wallace <wallacdj@gmail.com>
6 * This file is part of FFmpeg.
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.
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.
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
27 #define AES3_HEADER_LEN 4
29 typedef struct S302MEncContext {
30 uint8_t framing_index; /* Set for even channels on multiple of 192 samples */
33 static av_cold int s302m_encode_init(AVCodecContext *avctx)
35 S302MEncContext *s = avctx->priv_data;
37 if (avctx->channels & 1 || avctx->channels > 8) {
38 av_log(avctx, AV_LOG_ERROR,
39 "Encoding %d channel(s) is not allowed. Only 2, 4, 6 and 8 channels are supported.\n",
41 return AVERROR(EINVAL);
44 switch (avctx->sample_fmt) {
45 case AV_SAMPLE_FMT_S16:
46 avctx->bits_per_raw_sample = 16;
48 case AV_SAMPLE_FMT_S32:
49 if (avctx->bits_per_raw_sample > 20) {
50 if (avctx->bits_per_raw_sample > 24)
51 av_log(avctx, AV_LOG_WARNING, "encoding as 24 bits-per-sample\n");
52 avctx->bits_per_raw_sample = 24;
53 } else if (!avctx->bits_per_raw_sample) {
54 avctx->bits_per_raw_sample = 24;
55 } else if (avctx->bits_per_raw_sample <= 20) {
56 avctx->bits_per_raw_sample = 20;
60 avctx->frame_size = 0;
61 avctx->bit_rate = 48000 * avctx->channels *
62 (avctx->bits_per_raw_sample + 4);
68 static int s302m_encode2_frame(AVCodecContext *avctx, AVPacket *avpkt,
69 const AVFrame *frame, int *got_packet_ptr)
71 S302MEncContext *s = avctx->priv_data;
72 const int buf_size = AES3_HEADER_LEN +
75 (avctx->bits_per_raw_sample + 4)) / 8;
80 if ((ret = ff_alloc_packet2(avctx, avpkt, buf_size)) < 0)
84 init_put_bits(&pb, o, buf_size * 8);
85 put_bits(&pb, 16, buf_size - AES3_HEADER_LEN);
86 put_bits(&pb, 2, (avctx->channels - 2) >> 1); // number of channels
87 put_bits(&pb, 8, 0); // channel ID
88 put_bits(&pb, 2, (avctx->bits_per_raw_sample - 16) / 4); // bits per samples (0 = 16bit, 1 = 20bit, 2 = 24bit)
89 put_bits(&pb, 4, 0); // alignments
93 if (avctx->bits_per_raw_sample == 24) {
94 const uint32_t *samples = (uint32_t *)frame->data[0];
96 for (c = 0; c < frame->nb_samples; c++) {
97 uint8_t vucf = s->framing_index == 0 ? 0x10: 0;
99 for (channels = 0; channels < avctx->channels; channels += 2) {
100 o[0] = ff_reverse[(samples[0] & 0x0000FF00) >> 8];
101 o[1] = ff_reverse[(samples[0] & 0x00FF0000) >> 16];
102 o[2] = ff_reverse[(samples[0] & 0xFF000000) >> 24];
103 o[3] = ff_reverse[(samples[1] & 0x00000F00) >> 4] | vucf;
104 o[4] = ff_reverse[(samples[1] & 0x000FF000) >> 12];
105 o[5] = ff_reverse[(samples[1] & 0x0FF00000) >> 20];
106 o[6] = ff_reverse[(samples[1] & 0xF0000000) >> 28];
112 if (s->framing_index >= 192)
113 s->framing_index = 0;
115 } else if (avctx->bits_per_raw_sample == 20) {
116 const uint32_t *samples = (uint32_t *)frame->data[0];
118 for (c = 0; c < frame->nb_samples; c++) {
119 uint8_t vucf = s->framing_index == 0 ? 0x80: 0;
121 for (channels = 0; channels < avctx->channels; channels += 2) {
122 o[0] = ff_reverse[ (samples[0] & 0x000FF000) >> 12];
123 o[1] = ff_reverse[ (samples[0] & 0x0FF00000) >> 20];
124 o[2] = ff_reverse[((samples[0] & 0xF0000000) >> 28) | vucf];
125 o[3] = ff_reverse[ (samples[1] & 0x000FF000) >> 12];
126 o[4] = ff_reverse[ (samples[1] & 0x0FF00000) >> 20];
127 o[5] = ff_reverse[ (samples[1] & 0xF0000000) >> 28];
133 if (s->framing_index >= 192)
134 s->framing_index = 0;
136 } else if (avctx->bits_per_raw_sample == 16) {
137 const uint16_t *samples = (uint16_t *)frame->data[0];
139 for (c = 0; c < frame->nb_samples; c++) {
140 uint8_t vucf = s->framing_index == 0 ? 0x10 : 0;
142 for (channels = 0; channels < avctx->channels; channels += 2) {
143 o[0] = ff_reverse[ samples[0] & 0xFF];
144 o[1] = ff_reverse[(samples[0] & 0xFF00) >> 8];
145 o[2] = ff_reverse[(samples[1] & 0x0F) << 4] | vucf;
146 o[3] = ff_reverse[(samples[1] & 0x0FF0) >> 4];
147 o[4] = ff_reverse[(samples[1] & 0xF000) >> 12];
154 if (s->framing_index >= 192)
155 s->framing_index = 0;
164 AVCodec ff_s302m_encoder = {
166 .long_name = NULL_IF_CONFIG_SMALL("SMPTE 302M"),
167 .type = AVMEDIA_TYPE_AUDIO,
168 .id = CODEC_ID_S302M,
169 .priv_data_size = sizeof(S302MEncContext),
170 .init = s302m_encode_init,
171 .encode2 = s302m_encode2_frame,
172 .sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S32,
174 AV_SAMPLE_FMT_NONE },
175 .capabilities = CODEC_CAP_VARIABLE_FRAME_SIZE | CODEC_CAP_EXPERIMENTAL,
176 .supported_samplerates = (const int[]) { 48000, 0 },