| /* |
| * LPCM codecs for PCM formats found in Video DVD streams |
| * Copyright (c) 2018 Paul B Mahol |
| * |
| * 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 "bytestream.h" |
| #include "internal.h" |
| |
| typedef struct PCMDVDContext { |
| uint8_t header[3]; // Header added to every frame |
| int block_size; // Size of a block of samples in bytes |
| int samples_per_block; // Number of samples per channel per block |
| int groups_per_block; // Number of 20/24-bit sample groups per block |
| uint8_t *extra_samples; // Pointer to leftover samples from a frame |
| int extra_sample_count; // Number of leftover samples in the buffer |
| } PCMDVDContext; |
| |
| static av_cold int pcm_dvd_encode_init(AVCodecContext *avctx) |
| { |
| PCMDVDContext *s = avctx->priv_data; |
| int quant, freq, frame_size; |
| |
| switch (avctx->sample_rate) { |
| case 48000: |
| freq = 0; |
| break; |
| case 96000: |
| freq = 1; |
| break; |
| } |
| |
| switch (avctx->sample_fmt) { |
| case AV_SAMPLE_FMT_S16: |
| avctx->bits_per_coded_sample = 16; |
| quant = 0; |
| break; |
| case AV_SAMPLE_FMT_S32: |
| avctx->bits_per_coded_sample = 24; |
| quant = 2; |
| break; |
| } |
| |
| avctx->bits_per_coded_sample = 16 + quant * 4; |
| avctx->block_align = avctx->channels * avctx->bits_per_coded_sample / 8; |
| avctx->bit_rate = avctx->block_align * 8LL * avctx->sample_rate; |
| if (avctx->bit_rate > 9800000) { |
| av_log(avctx, AV_LOG_ERROR, "Too big bitrate: reduce sample rate, bitdepth or channels.\n"); |
| return AVERROR(EINVAL); |
| } |
| |
| if (avctx->sample_fmt == AV_SAMPLE_FMT_S16) { |
| s->samples_per_block = 1; |
| s->block_size = avctx->channels * 2; |
| frame_size = 2008 / s->block_size; |
| } else { |
| switch (avctx->channels) { |
| case 1: |
| case 2: |
| case 4: |
| /* one group has all the samples needed */ |
| s->block_size = 4 * avctx->bits_per_coded_sample / 8; |
| s->samples_per_block = 4 / avctx->channels; |
| s->groups_per_block = 1; |
| break; |
| case 8: |
| /* two groups have all the samples needed */ |
| s->block_size = 8 * avctx->bits_per_coded_sample / 8; |
| s->samples_per_block = 1; |
| s->groups_per_block = 2; |
| break; |
| default: |
| /* need avctx->channels groups */ |
| s->block_size = 4 * avctx->channels * |
| avctx->bits_per_coded_sample / 8; |
| s->samples_per_block = 4; |
| s->groups_per_block = avctx->channels; |
| break; |
| } |
| |
| frame_size = FFALIGN(2008 / s->block_size, s->samples_per_block); |
| } |
| |
| s->header[0] = 0x0c; |
| s->header[1] = (quant << 6) | (freq << 4) | (avctx->channels - 1); |
| s->header[2] = 0x80; |
| |
| if (!avctx->frame_size) |
| avctx->frame_size = frame_size; |
| |
| return 0; |
| } |
| |
| static int pcm_dvd_encode_frame(AVCodecContext *avctx, AVPacket *avpkt, |
| const AVFrame *frame, int *got_packet_ptr) |
| { |
| PCMDVDContext *s = avctx->priv_data; |
| int samples = frame->nb_samples * avctx->channels; |
| int64_t pkt_size = (frame->nb_samples / s->samples_per_block) * s->block_size + 3; |
| int blocks = (pkt_size - 3) / s->block_size; |
| const int16_t *src16; |
| const int32_t *src32; |
| PutByteContext pb; |
| int ret; |
| |
| if ((ret = ff_alloc_packet2(avctx, avpkt, pkt_size, 0)) < 0) |
| return ret; |
| |
| memcpy(avpkt->data, s->header, 3); |
| |
| src16 = (const int16_t *)frame->data[0]; |
| src32 = (const int32_t *)frame->data[0]; |
| |
| bytestream2_init_writer(&pb, avpkt->data + 3, avpkt->size - 3); |
| |
| switch (avctx->sample_fmt) { |
| case AV_SAMPLE_FMT_S16: |
| do { |
| bytestream2_put_be16(&pb, *src16++); |
| } while (--samples); |
| break; |
| case AV_SAMPLE_FMT_S32: |
| if (avctx->channels == 1) { |
| do { |
| for (int i = 2; i; i--) { |
| bytestream2_put_be16(&pb, src32[0] >> 16); |
| bytestream2_put_be16(&pb, src32[1] >> 16); |
| bytestream2_put_byte(&pb, (*src32++) >> 24); |
| bytestream2_put_byte(&pb, (*src32++) >> 24); |
| } |
| } while (--blocks); |
| } else { |
| do { |
| for (int i = s->groups_per_block; i; i--) { |
| bytestream2_put_be16(&pb, src32[0] >> 16); |
| bytestream2_put_be16(&pb, src32[1] >> 16); |
| bytestream2_put_be16(&pb, src32[2] >> 16); |
| bytestream2_put_be16(&pb, src32[3] >> 16); |
| bytestream2_put_byte(&pb, (*src32++) >> 24); |
| bytestream2_put_byte(&pb, (*src32++) >> 24); |
| bytestream2_put_byte(&pb, (*src32++) >> 24); |
| bytestream2_put_byte(&pb, (*src32++) >> 24); |
| } |
| } while (--blocks); |
| } |
| break; |
| } |
| |
| avpkt->pts = frame->pts; |
| avpkt->size = pkt_size; |
| avpkt->duration = ff_samples_to_time_base(avctx, frame->nb_samples); |
| *got_packet_ptr = 1; |
| |
| return 0; |
| } |
| |
| AVCodec ff_pcm_dvd_encoder = { |
| .name = "pcm_dvd", |
| .long_name = NULL_IF_CONFIG_SMALL("PCM signed 16|20|24-bit big-endian for DVD media"), |
| .type = AVMEDIA_TYPE_AUDIO, |
| .id = AV_CODEC_ID_PCM_DVD, |
| .priv_data_size = sizeof(PCMDVDContext), |
| .init = pcm_dvd_encode_init, |
| .encode2 = pcm_dvd_encode_frame, |
| .capabilities = AV_CODEC_CAP_SMALL_LAST_FRAME, |
| .supported_samplerates = (const int[]) { 48000, 96000, 0}, |
| .channel_layouts = (const uint64_t[]) { AV_CH_LAYOUT_MONO, |
| AV_CH_LAYOUT_STEREO, |
| AV_CH_LAYOUT_5POINT1, |
| AV_CH_LAYOUT_7POINT1, |
| 0 }, |
| .sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16, |
| AV_SAMPLE_FMT_S32, |
| AV_SAMPLE_FMT_NONE }, |
| .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE, |
| }; |