diff options
author | Paul B Mahol <onemda@gmail.com> | 2018-11-26 21:03:58 +0300 |
---|---|---|
committer | Paul B Mahol <onemda@gmail.com> | 2018-12-01 21:41:48 +0300 |
commit | e9967822e41213acb95e4a1b3a9bbfd240bc12c9 (patch) | |
tree | a24dc104527d99d95fa7891f13c4a4709a52b743 /libavcodec/pcm-dvdenc.c | |
parent | 1a89ae1df8585134b9524f736b71cee98de7895a (diff) |
avcodec: add PCM-DVD encoder
Fixes #6784.
Diffstat (limited to 'libavcodec/pcm-dvdenc.c')
-rw-r--r-- | libavcodec/pcm-dvdenc.c | 197 |
1 files changed, 197 insertions, 0 deletions
diff --git a/libavcodec/pcm-dvdenc.c b/libavcodec/pcm-dvdenc.c new file mode 100644 index 0000000000..d26eaf071c --- /dev/null +++ b/libavcodec/pcm-dvdenc.c @@ -0,0 +1,197 @@ +/* + * 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; +} + +static av_cold int pcm_dvd_encode_close(AVCodecContext *avctx) +{ + 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, + .close = pcm_dvd_encode_close, + .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 }, +}; |