| 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 | |
| 30 | typedef struct S302MEncContext { |
| 31 | uint8_t framing_index; /* Set for even channels on multiple of 192 samples */ |
| 32 | } S302MEncContext; |
| 33 | |
| 34 | static 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 | |
| 69 | static 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 ((ret = ff_alloc_packet2(avctx, avpkt, buf_size)) < 0) |
| 82 | return ret; |
| 83 | |
| 84 | o = avpkt->data; |
| 85 | init_put_bits(&pb, o, buf_size * 8); |
| 86 | put_bits(&pb, 16, buf_size - AES3_HEADER_LEN); |
| 87 | put_bits(&pb, 2, (avctx->channels - 2) >> 1); // number of channels |
| 88 | put_bits(&pb, 8, 0); // channel ID |
| 89 | put_bits(&pb, 2, (avctx->bits_per_raw_sample - 16) / 4); // bits per samples (0 = 16bit, 1 = 20bit, 2 = 24bit) |
| 90 | put_bits(&pb, 4, 0); // alignments |
| 91 | flush_put_bits(&pb); |
| 92 | o += AES3_HEADER_LEN; |
| 93 | |
| 94 | if (avctx->bits_per_raw_sample == 24) { |
| 95 | const uint32_t *samples = (uint32_t *)frame->data[0]; |
| 96 | |
| 97 | for (c = 0; c < frame->nb_samples; c++) { |
| 98 | uint8_t vucf = s->framing_index == 0 ? 0x10: 0; |
| 99 | |
| 100 | for (channels = 0; channels < avctx->channels; channels += 2) { |
| 101 | o[0] = ff_reverse[(samples[0] & 0x0000FF00) >> 8]; |
| 102 | o[1] = ff_reverse[(samples[0] & 0x00FF0000) >> 16]; |
| 103 | o[2] = ff_reverse[(samples[0] & 0xFF000000) >> 24]; |
| 104 | o[3] = ff_reverse[(samples[1] & 0x00000F00) >> 4] | vucf; |
| 105 | o[4] = ff_reverse[(samples[1] & 0x000FF000) >> 12]; |
| 106 | o[5] = ff_reverse[(samples[1] & 0x0FF00000) >> 20]; |
| 107 | o[6] = ff_reverse[(samples[1] & 0xF0000000) >> 28]; |
| 108 | o += 7; |
| 109 | samples += 2; |
| 110 | } |
| 111 | |
| 112 | s->framing_index++; |
| 113 | if (s->framing_index >= 192) |
| 114 | s->framing_index = 0; |
| 115 | } |
| 116 | } else if (avctx->bits_per_raw_sample == 20) { |
| 117 | const uint32_t *samples = (uint32_t *)frame->data[0]; |
| 118 | |
| 119 | for (c = 0; c < frame->nb_samples; c++) { |
| 120 | uint8_t vucf = s->framing_index == 0 ? 0x80: 0; |
| 121 | |
| 122 | for (channels = 0; channels < avctx->channels; channels += 2) { |
| 123 | o[0] = ff_reverse[ (samples[0] & 0x000FF000) >> 12]; |
| 124 | o[1] = ff_reverse[ (samples[0] & 0x0FF00000) >> 20]; |
| 125 | o[2] = ff_reverse[((samples[0] & 0xF0000000) >> 28) | vucf]; |
| 126 | o[3] = ff_reverse[ (samples[1] & 0x000FF000) >> 12]; |
| 127 | o[4] = ff_reverse[ (samples[1] & 0x0FF00000) >> 20]; |
| 128 | o[5] = ff_reverse[ (samples[1] & 0xF0000000) >> 28]; |
| 129 | o += 6; |
| 130 | samples += 2; |
| 131 | } |
| 132 | |
| 133 | s->framing_index++; |
| 134 | if (s->framing_index >= 192) |
| 135 | s->framing_index = 0; |
| 136 | } |
| 137 | } else if (avctx->bits_per_raw_sample == 16) { |
| 138 | const uint16_t *samples = (uint16_t *)frame->data[0]; |
| 139 | |
| 140 | for (c = 0; c < frame->nb_samples; c++) { |
| 141 | uint8_t vucf = s->framing_index == 0 ? 0x10 : 0; |
| 142 | |
| 143 | for (channels = 0; channels < avctx->channels; channels += 2) { |
| 144 | o[0] = ff_reverse[ samples[0] & 0xFF]; |
| 145 | o[1] = ff_reverse[(samples[0] & 0xFF00) >> 8]; |
| 146 | o[2] = ff_reverse[(samples[1] & 0x0F) << 4] | vucf; |
| 147 | o[3] = ff_reverse[(samples[1] & 0x0FF0) >> 4]; |
| 148 | o[4] = ff_reverse[(samples[1] & 0xF000) >> 12]; |
| 149 | o += 5; |
| 150 | samples += 2; |
| 151 | |
| 152 | } |
| 153 | |
| 154 | s->framing_index++; |
| 155 | if (s->framing_index >= 192) |
| 156 | s->framing_index = 0; |
| 157 | } |
| 158 | } |
| 159 | |
| 160 | *got_packet_ptr = 1; |
| 161 | |
| 162 | return 0; |
| 163 | } |
| 164 | |
| 165 | AVCodec ff_s302m_encoder = { |
| 166 | .name = "s302m", |
| 167 | .long_name = NULL_IF_CONFIG_SMALL("SMPTE 302M"), |
| 168 | .type = AVMEDIA_TYPE_AUDIO, |
| 169 | .id = AV_CODEC_ID_S302M, |
| 170 | .priv_data_size = sizeof(S302MEncContext), |
| 171 | .init = s302m_encode_init, |
| 172 | .encode2 = s302m_encode2_frame, |
| 173 | .sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S32, |
| 174 | AV_SAMPLE_FMT_S16, |
| 175 | AV_SAMPLE_FMT_NONE }, |
| 176 | .capabilities = CODEC_CAP_VARIABLE_FRAME_SIZE | CODEC_CAP_EXPERIMENTAL, |
| 177 | .supported_samplerates = (const int[]) { 48000, 0 }, |
| 178 | }; |