/* * SMPTE 302M encoder * Copyright (c) 2010 Google, Inc. * Copyright (c) 2013 Darryl Wallace * * 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 */ #include "avcodec.h" #include "internal.h" #include "mathops.h" #include "put_bits.h" #define AES3_HEADER_LEN 4 typedef struct S302MEncContext { uint8_t framing_index; /* Set for even channels on multiple of 192 samples */ } S302MEncContext; static av_cold int s302m_encode_init(AVCodecContext *avctx) { S302MEncContext *s = avctx->priv_data; if (avctx->channels & 1 || avctx->channels > 8) { av_log(avctx, AV_LOG_ERROR, "Encoding %d channel(s) is not allowed. Only 2, 4, 6 and 8 channels are supported.\n", avctx->channels); return AVERROR(EINVAL); } switch (avctx->sample_fmt) { case AV_SAMPLE_FMT_S16: avctx->bits_per_raw_sample = 16; break; case AV_SAMPLE_FMT_S32: if (avctx->bits_per_raw_sample > 20) { if (avctx->bits_per_raw_sample > 24) av_log(avctx, AV_LOG_WARNING, "encoding as 24 bits-per-sample\n"); avctx->bits_per_raw_sample = 24; } else if (!avctx->bits_per_raw_sample) { avctx->bits_per_raw_sample = 24; } else if (avctx->bits_per_raw_sample <= 20) { avctx->bits_per_raw_sample = 20; } } avctx->frame_size = 0; avctx->bit_rate = 48000 * avctx->channels * (avctx->bits_per_raw_sample + 4); s->framing_index = 0; return 0; } static int s302m_encode2_frame(AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame, int *got_packet_ptr) { S302MEncContext *s = avctx->priv_data; const int buf_size = AES3_HEADER_LEN + (frame->nb_samples * avctx->channels * (avctx->bits_per_raw_sample + 4)) / 8; int ret, c, channels; uint8_t *o; PutBitContext pb; if (buf_size - AES3_HEADER_LEN > UINT16_MAX) { av_log(avctx, AV_LOG_ERROR, "number of samples in frame too big\n"); return AVERROR(EINVAL); } if ((ret = ff_alloc_packet2(avctx, avpkt, buf_size, 0)) < 0) return ret; o = avpkt->data; init_put_bits(&pb, o, buf_size); put_bits(&pb, 16, buf_size - AES3_HEADER_LEN); put_bits(&pb, 2, (avctx->channels - 2) >> 1); // number of channels put_bits(&pb, 8, 0); // channel ID put_bits(&pb, 2, (avctx->bits_per_raw_sample - 16) / 4); // bits per samples (0 = 16bit, 1 = 20bit, 2 = 24bit) put_bits(&pb, 4, 0); // alignments flush_put_bits(&pb); o += AES3_HEADER_LEN; if (avctx->bits_per_raw_sample == 24) { const uint32_t *samples = (uint32_t *)frame->data[0]; for (c = 0; c < frame->nb_samples; c++) { uint8_t vucf = s->framing_index == 0 ? 0x10: 0; for (channels = 0; channels < avctx->channels; channels += 2) { o[0] = ff_reverse[(samples[0] & 0x0000FF00) >> 8]; o[1] = ff_reverse[(samples[0] & 0x00FF0000) >> 16]; o[2] = ff_reverse[(samples[0] & 0xFF000000) >> 24]; o[3] = ff_reverse[(samples[1] & 0x00000F00) >> 4] | vucf; o[4] = ff_reverse[(samples[1] & 0x000FF000) >> 12]; o[5] = ff_reverse[(samples[1] & 0x0FF00000) >> 20]; o[6] = ff_reverse[(samples[1] & 0xF0000000) >> 28]; o += 7; samples += 2; } s->framing_index++; if (s->framing_index >= 192) s->framing_index = 0; } } else if (avctx->bits_per_raw_sample == 20) { const uint32_t *samples = (uint32_t *)frame->data[0]; for (c = 0; c < frame->nb_samples; c++) { uint8_t vucf = s->framing_index == 0 ? 0x80: 0; for (channels = 0; channels < avctx->channels; channels += 2) { o[0] = ff_reverse[ (samples[0] & 0x000FF000) >> 12]; o[1] = ff_reverse[ (samples[0] & 0x0FF00000) >> 20]; o[2] = ff_reverse[((samples[0] & 0xF0000000) >> 28) | vucf]; o[3] = ff_reverse[ (samples[1] & 0x000FF000) >> 12]; o[4] = ff_reverse[ (samples[1] & 0x0FF00000) >> 20]; o[5] = ff_reverse[ (samples[1] & 0xF0000000) >> 28]; o += 6; samples += 2; } s->framing_index++; if (s->framing_index >= 192) s->framing_index = 0; } } else if (avctx->bits_per_raw_sample == 16) { const uint16_t *samples = (uint16_t *)frame->data[0]; for (c = 0; c < frame->nb_samples; c++) { uint8_t vucf = s->framing_index == 0 ? 0x10 : 0; for (channels = 0; channels < avctx->channels; channels += 2) { o[0] = ff_reverse[ samples[0] & 0xFF]; o[1] = ff_reverse[(samples[0] & 0xFF00) >> 8]; o[2] = ff_reverse[(samples[1] & 0x0F) << 4] | vucf; o[3] = ff_reverse[(samples[1] & 0x0FF0) >> 4]; o[4] = ff_reverse[(samples[1] & 0xF000) >> 12]; o += 5; samples += 2; } s->framing_index++; if (s->framing_index >= 192) s->framing_index = 0; } } *got_packet_ptr = 1; return 0; } AVCodec ff_s302m_encoder = { .name = "s302m", .long_name = NULL_IF_CONFIG_SMALL("SMPTE 302M"), .type = AVMEDIA_TYPE_AUDIO, .id = AV_CODEC_ID_S302M, .priv_data_size = sizeof(S302MEncContext), .init = s302m_encode_init, .encode2 = s302m_encode2_frame, .sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S32, AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_NONE }, .capabilities = AV_CODEC_CAP_VARIABLE_FRAME_SIZE | AV_CODEC_CAP_EXPERIMENTAL, .supported_samplerates = (const int[]) { 48000, 0 }, .channel_layouts = (const uint64_t[]) { AV_CH_LAYOUT_STEREO, AV_CH_LAYOUT_QUAD, AV_CH_LAYOUT_5POINT1_BACK, AV_CH_LAYOUT_5POINT1_BACK | AV_CH_LAYOUT_STEREO_DOWNMIX, 0 }, };