From 751526c456d09bd22a6316196219d79876ae74f1 Mon Sep 17 00:00:00 2001 From: Paul B Mahol Date: Mon, 19 Sep 2022 22:14:05 +0200 Subject: [PATCH 1/2] avcodec: add APAC decoder Signed-off-by: Paul B Mahol --- libavcodec/Makefile | 1 + libavcodec/allcodecs.c | 1 + libavcodec/apac.c | 269 ++++++++++++++++++++++++++++++++++++++++ libavcodec/codec_desc.c | 7 ++ libavcodec/codec_id.h | 1 + 5 files changed, 279 insertions(+) create mode 100644 libavcodec/apac.c diff --git a/libavcodec/Makefile b/libavcodec/Makefile index c836252664..b9aa6efaac 100644 --- a/libavcodec/Makefile +++ b/libavcodec/Makefile @@ -214,6 +214,7 @@ OBJS-$(CONFIG_AMRWB_DECODER) += amrwbdec.o celp_filters.o \ OBJS-$(CONFIG_AMV_ENCODER) += mjpegenc.o mjpegenc_common.o OBJS-$(CONFIG_ANM_DECODER) += anm.o OBJS-$(CONFIG_ANSI_DECODER) += ansi.o cga_data.o +OBJS-$(CONFIG_APAC_DECODER) += apac.o OBJS-$(CONFIG_APE_DECODER) += apedec.o OBJS-$(CONFIG_APTX_DECODER) += aptxdec.o aptx.o OBJS-$(CONFIG_APTX_ENCODER) += aptxenc.o aptx.o diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c index 447225e26b..fc88e25fda 100644 --- a/libavcodec/allcodecs.c +++ b/libavcodec/allcodecs.c @@ -432,6 +432,7 @@ extern const FFCodec ff_alac_decoder; extern const FFCodec ff_als_decoder; extern const FFCodec ff_amrnb_decoder; extern const FFCodec ff_amrwb_decoder; +extern const FFCodec ff_apac_decoder; extern const FFCodec ff_ape_decoder; extern const FFCodec ff_aptx_encoder; extern const FFCodec ff_aptx_decoder; diff --git a/libavcodec/apac.c b/libavcodec/apac.c new file mode 100644 index 0000000000..2dc9aacd44 --- /dev/null +++ b/libavcodec/apac.c @@ -0,0 +1,269 @@ +/* + * APAC audio decoder + * + * 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 "libavutil/audio_fifo.h" +#include "libavutil/internal.h" +#include "libavutil/intreadwrite.h" +#include "avcodec.h" +#include "codec_internal.h" +#include "decode.h" +#include "get_bits.h" + +typedef struct ChContext { + int have_code; + int last_sample; + int last_delta; + int bit_length; + int block_length; + uint8_t block[32 * 2]; + AVAudioFifo *samples; +} ChContext; + +typedef struct APACContext { + GetBitContext gb; + int skip; + + int cur_ch; + ChContext ch[2]; + + uint8_t *bitstream; + int64_t max_framesize; + int bitstream_size; + int bitstream_index; +} APACContext; + +static av_cold int apac_close(AVCodecContext *avctx) +{ + APACContext *s = avctx->priv_data; + + av_freep(&s->bitstream); + s->bitstream_size = 0; + + for (int ch = 0; ch < avctx->ch_layout.nb_channels; ch++) { + ChContext *c = &s->ch[ch]; + + av_audio_fifo_free(c->samples); + } + + return 0; +} + +static av_cold int apac_init(AVCodecContext *avctx) +{ + APACContext *s = avctx->priv_data; + + if (avctx->bits_per_coded_sample > 8) + avctx->sample_fmt = AV_SAMPLE_FMT_S16P; + else + avctx->sample_fmt = AV_SAMPLE_FMT_U8P; + + if (avctx->ch_layout.nb_channels < 1 || + avctx->ch_layout.nb_channels > 2) + return AVERROR_INVALIDDATA; + + for (int ch = 0; ch < avctx->ch_layout.nb_channels; ch++) { + ChContext *c = &s->ch[ch]; + + c->bit_length = avctx->bits_per_coded_sample; + c->block_length = 8; + c->have_code = 0; + c->samples = av_audio_fifo_alloc(avctx->sample_fmt, 1, 1024); + if (!c->samples) + return AVERROR(ENOMEM); + } + + s->max_framesize = 1024; + s->bitstream = av_realloc_f(s->bitstream, s->max_framesize + AV_INPUT_BUFFER_PADDING_SIZE, sizeof(*s->bitstream)); + if (!s->bitstream) + return AVERROR(ENOMEM); + + return 0; +} + +static int get_code(ChContext *c, GetBitContext *gb) +{ + if (get_bits1(gb)) { + int code = get_bits(gb, 2); + + switch (code) { + case 0: + c->bit_length--; + break; + case 1: + c->bit_length++; + break; + case 2: + c->bit_length = get_bits(gb, 5); + break; + case 3: + c->block_length = get_bits(gb, 4); + return 1; + } + } + + return 0; +} + +static int apac_decode(AVCodecContext *avctx, AVFrame *frame, + int *got_frame_ptr, AVPacket *pkt) +{ + APACContext *s = avctx->priv_data; + GetBitContext *gb = &s->gb; + int ret, n, buf_size, input_buf_size; + const uint8_t *buf; + int nb_samples; + + if (!pkt->size && s->bitstream_size <= 0) { + *got_frame_ptr = 0; + return 0; + } + + buf_size = pkt->size; + input_buf_size = buf_size; + + if (s->bitstream_index > 0 && s->bitstream_size > 0) { + memmove(s->bitstream, &s->bitstream[s->bitstream_index], s->bitstream_size); + s->bitstream_index = 0; + } + + if (s->bitstream_index + s->bitstream_size + buf_size > s->max_framesize) { + s->bitstream = av_realloc_f(s->bitstream, s->bitstream_index + + s->bitstream_size + + buf_size + AV_INPUT_BUFFER_PADDING_SIZE, + sizeof(*s->bitstream)); + if (!s->bitstream) + return AVERROR(ENOMEM); + s->max_framesize = s->bitstream_index + s->bitstream_size + buf_size; + } + if (pkt->data) + memcpy(&s->bitstream[s->bitstream_index + s->bitstream_size], pkt->data, buf_size); + buf = &s->bitstream[s->bitstream_index]; + buf_size += s->bitstream_size; + s->bitstream_size = buf_size; + + frame->nb_samples = s->bitstream_size * 16 * 8; + if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) + return ret; + + if ((ret = init_get_bits8(gb, buf, buf_size)) < 0) + return ret; + + skip_bits(gb, s->skip); + s->skip = 0; + + while (get_bits_left(gb) > 0) { + for (int ch = s->cur_ch; ch < avctx->ch_layout.nb_channels; ch++) { + ChContext *c = &s->ch[ch]; + int16_t *dst16 = (int16_t *)c->block; + uint8_t *dst8 = (uint8_t *)c->block; + void *samples[4]; + + samples[0] = &c->block[0]; + if (get_bits_left(gb) < 16 && pkt->size) { + s->cur_ch = ch; + goto end; + } + + if (!c->have_code && get_code(c, gb)) + get_code(c, gb); + c->have_code = 0; + + if (c->block_length <= 0) + continue; + + if (c->bit_length < 0 || + c->bit_length > 17) { + c->bit_length = avctx->bits_per_coded_sample; + return AVERROR_INVALIDDATA; + } + + if (get_bits_left(gb) < c->block_length * c->bit_length && pkt->size) { + c->have_code = 1; + s->cur_ch = ch; + goto end; + } + + for (int i = 0; i < c->block_length; i++) { + int val = get_bits_long(gb, c->bit_length); + int delta = (val & 1) ? ~(val >> 1) : (val >> 1); + int sample; + + delta += c->last_delta; + sample = c->last_sample + delta; + c->last_delta = delta; + c->last_sample = sample; + + switch (avctx->sample_fmt) { + case AV_SAMPLE_FMT_S16P: + dst16[i] = sample; + break; + case AV_SAMPLE_FMT_U8P: + dst8[i] = sample; + break; + } + } + + av_audio_fifo_write(c->samples, samples, c->block_length); + } + + s->cur_ch = 0; + } +end: + nb_samples = frame->nb_samples; + for (int ch = 0; ch < avctx->ch_layout.nb_channels; ch++) + nb_samples = FFMIN(av_audio_fifo_size(s->ch[ch].samples), nb_samples); + + frame->nb_samples = nb_samples; + for (int ch = 0; ch < avctx->ch_layout.nb_channels; ch++) { + void *samples[1] = { frame->extended_data[ch] }; + av_audio_fifo_read(s->ch[ch].samples, samples, nb_samples); + } + + s->skip = get_bits_count(gb) - 8 * (get_bits_count(gb) / 8); + n = get_bits_count(gb) / 8; + + if (nb_samples > 0 || pkt->size) + *got_frame_ptr = 1; + + if (s->bitstream_size > 0) { + s->bitstream_index += n; + s->bitstream_size -= n; + return input_buf_size; + } + return n; +} + +const FFCodec ff_apac_decoder = { + .p.name = "apac", + CODEC_LONG_NAME("Marian's A-pac audio"), + .p.type = AVMEDIA_TYPE_AUDIO, + .p.id = AV_CODEC_ID_APAC, + .priv_data_size = sizeof(APACContext), + .init = apac_init, + FF_CODEC_DECODE_CB(apac_decode), + .close = apac_close, + .p.capabilities = AV_CODEC_CAP_DELAY | + AV_CODEC_CAP_DR1 | + AV_CODEC_CAP_SUBFRAMES, + .caps_internal = FF_CODEC_CAP_INIT_CLEANUP, + .p.sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_U8P, + AV_SAMPLE_FMT_S16P, + AV_SAMPLE_FMT_NONE }, +}; diff --git a/libavcodec/codec_desc.c b/libavcodec/codec_desc.c index 648c518b3c..e8e1529401 100644 --- a/libavcodec/codec_desc.c +++ b/libavcodec/codec_desc.c @@ -3304,6 +3304,13 @@ static const AVCodecDescriptor codec_descriptors[] = { .long_name = NULL_IF_CONFIG_SMALL("Micronas SC-4 Audio"), .props = AV_CODEC_PROP_LOSSY | AV_CODEC_PROP_INTRA_ONLY, }, + { + .id = AV_CODEC_ID_APAC, + .type = AVMEDIA_TYPE_AUDIO, + .name = "apac", + .long_name = NULL_IF_CONFIG_SMALL("Marian's A-pac audio"), + .props = AV_CODEC_PROP_INTRA_ONLY | AV_CODEC_PROP_LOSSLESS, + }, /* subtitle codecs */ { diff --git a/libavcodec/codec_id.h b/libavcodec/codec_id.h index bc8226ff07..9c01ea9750 100644 --- a/libavcodec/codec_id.h +++ b/libavcodec/codec_id.h @@ -529,6 +529,7 @@ enum AVCodecID { AV_CODEC_ID_DFPWM, AV_CODEC_ID_BONK, AV_CODEC_ID_MISC4, + AV_CODEC_ID_APAC, /* subtitle codecs */ AV_CODEC_ID_FIRST_SUBTITLE = 0x17000, ///< A dummy ID pointing at the start of subtitle codecs. -- 2.37.2