/* * DCA parser * Copyright (C) 2004 Gildas Bazin * Copyright (C) 2004 Benjamin Zores * Copyright (C) 2006 Benjamin Larsson * Copyright (C) 2007 Konstantin Shishkov * * 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 "dca.h" #include "dca_core.h" #include "dca_exss.h" #include "dca_lbr.h" #include "dca_syncwords.h" #include "get_bits.h" #include "parser.h" typedef struct DCAParseContext { ParseContext pc; uint32_t lastmarker; int size; int framesize; unsigned int startpos; DCAExssParser exss; unsigned int sr_code; } DCAParseContext; #define IS_CORE_MARKER(state) \ (((state & 0xFFFFFFFFF0FF) == (((uint64_t)DCA_SYNCWORD_CORE_14B_LE << 16) | 0xF007)) || \ ((state & 0xFFFFFFFFFFF0) == (((uint64_t)DCA_SYNCWORD_CORE_14B_BE << 16) | 0x07F0)) || \ ((state & 0xFFFFFFFF00FC) == (((uint64_t)DCA_SYNCWORD_CORE_LE << 16) | 0x00FC)) || \ ((state & 0xFFFFFFFFFC00) == (((uint64_t)DCA_SYNCWORD_CORE_BE << 16) | 0xFC00))) #define IS_EXSS_MARKER(state) ((state & 0xFFFFFFFF) == DCA_SYNCWORD_SUBSTREAM) #define IS_MARKER(state) (IS_CORE_MARKER(state) || IS_EXSS_MARKER(state)) #define CORE_MARKER(state) ((state >> 16) & 0xFFFFFFFF) #define EXSS_MARKER(state) (state & 0xFFFFFFFF) #define STATE_LE(state) (((state & 0xFF00FF00) >> 8) | ((state & 0x00FF00FF) << 8)) #define STATE_14(state) (((state & 0x3FFF0000) >> 8) | ((state & 0x00003FFF) >> 6)) #define CORE_FRAMESIZE(state) (((state >> 4) & 0x3FFF) + 1) #define EXSS_FRAMESIZE(state) ((state & 0x2000000000) ? \ ((state >> 5) & 0xFFFFF) + 1 : \ ((state >> 13) & 0x0FFFF) + 1) /** * Find the end of the current frame in the bitstream. * @return the position of the first byte of the next frame, or -1 */ static int dca_find_frame_end(DCAParseContext *pc1, const uint8_t *buf, int buf_size) { int start_found, size, i; uint64_t state; ParseContext *pc = &pc1->pc; start_found = pc->frame_start_found; state = pc->state64; size = pc1->size; i = 0; if (!start_found) { for (; i < buf_size; i++) { size++; state = (state << 8) | buf[i]; if (IS_MARKER(state) && (!pc1->lastmarker || pc1->lastmarker == CORE_MARKER(state) || pc1->lastmarker == DCA_SYNCWORD_SUBSTREAM)) { if (!pc1->lastmarker) pc1->startpos = IS_EXSS_MARKER(state) ? size - 4 : size - 6; if (IS_EXSS_MARKER(state)) pc1->lastmarker = EXSS_MARKER(state); else pc1->lastmarker = CORE_MARKER(state); start_found = 1; size = 0; i++; break; } } } if (start_found) { for (; i < buf_size; i++) { size++; state = (state << 8) | buf[i]; if (start_found == 1) { switch (pc1->lastmarker) { case DCA_SYNCWORD_CORE_BE: if (size == 2) { pc1->framesize = CORE_FRAMESIZE(state); start_found = 2; } break; case DCA_SYNCWORD_CORE_LE: if (size == 2) { pc1->framesize = CORE_FRAMESIZE(STATE_LE(state)); start_found = 4; } break; case DCA_SYNCWORD_CORE_14B_BE: if (size == 4) { pc1->framesize = CORE_FRAMESIZE(STATE_14(state)); start_found = 4; } break; case DCA_SYNCWORD_CORE_14B_LE: if (size == 4) { pc1->framesize = CORE_FRAMESIZE(STATE_14(STATE_LE(state))); start_found = 4; } break; case DCA_SYNCWORD_SUBSTREAM: if (size == 6) { pc1->framesize = EXSS_FRAMESIZE(state); start_found = 4; } break; default: av_assert0(0); } continue; } if (start_found == 2 && IS_EXSS_MARKER(state) && pc1->framesize <= size + 2) { pc1->framesize = size + 2; start_found = 3; continue; } if (start_found == 3) { if (size == pc1->framesize + 4) { pc1->framesize += EXSS_FRAMESIZE(state); start_found = 4; } continue; } if (pc1->framesize > size) continue; if (IS_MARKER(state) && (pc1->lastmarker == CORE_MARKER(state) || pc1->lastmarker == DCA_SYNCWORD_SUBSTREAM)) { pc->frame_start_found = 0; pc->state64 = -1; pc1->size = 0; return IS_EXSS_MARKER(state) ? i - 3 : i - 5; } } } pc->frame_start_found = start_found; pc->state64 = state; pc1->size = size; return END_NOT_FOUND; } static av_cold int dca_parse_init(AVCodecParserContext *s) { DCAParseContext *pc1 = s->priv_data; pc1->lastmarker = 0; pc1->sr_code = -1; return 0; } static int dca_parse_params(DCAParseContext *pc1, const uint8_t *buf, int buf_size, int *duration, int *sample_rate, int *profile) { DCAExssAsset *asset = &pc1->exss.assets[0]; GetBitContext gb; DCACoreFrameHeader h; uint8_t hdr[DCA_CORE_FRAME_HEADER_SIZE + AV_INPUT_BUFFER_PADDING_SIZE] = { 0 }; int ret, frame_size; if (buf_size < DCA_CORE_FRAME_HEADER_SIZE) return AVERROR_INVALIDDATA; if (AV_RB32(buf) == DCA_SYNCWORD_SUBSTREAM) { if ((ret = ff_dca_exss_parse(&pc1->exss, buf, buf_size)) < 0) return ret; if (asset->extension_mask & DCA_EXSS_LBR) { if ((ret = init_get_bits8(&gb, buf + asset->lbr_offset, asset->lbr_size)) < 0) return ret; if (get_bits_long(&gb, 32) != DCA_SYNCWORD_LBR) return AVERROR_INVALIDDATA; switch (get_bits(&gb, 8)) { case DCA_LBR_HEADER_DECODER_INIT: pc1->sr_code = get_bits(&gb, 8); case DCA_LBR_HEADER_SYNC_ONLY: break; default: return AVERROR_INVALIDDATA; } if (pc1->sr_code >= FF_ARRAY_ELEMS(ff_dca_sampling_freqs)) return AVERROR_INVALIDDATA; *sample_rate = ff_dca_sampling_freqs[pc1->sr_code]; *duration = 1024 << ff_dca_freq_ranges[pc1->sr_code]; *profile = FF_PROFILE_DTS_EXPRESS; return 0; } if (asset->extension_mask & DCA_EXSS_XLL) { int nsamples_log2; if ((ret = init_get_bits8(&gb, buf + asset->xll_offset, asset->xll_size)) < 0) return ret; if (get_bits_long(&gb, 32) != DCA_SYNCWORD_XLL) return AVERROR_INVALIDDATA; if (get_bits(&gb, 4)) return AVERROR_INVALIDDATA; skip_bits(&gb, 8); skip_bits_long(&gb, get_bits(&gb, 5) + 1); skip_bits(&gb, 4); nsamples_log2 = get_bits(&gb, 4) + get_bits(&gb, 4); if (nsamples_log2 > 24) return AVERROR_INVALIDDATA; *sample_rate = asset->max_sample_rate; *duration = (1 + (*sample_rate > 96000)) << nsamples_log2; *profile = FF_PROFILE_DTS_HD_MA; return 0; } return AVERROR_INVALIDDATA; } if ((ret = avpriv_dca_convert_bitstream(buf, DCA_CORE_FRAME_HEADER_SIZE, hdr, DCA_CORE_FRAME_HEADER_SIZE)) < 0) return ret; if (avpriv_dca_parse_core_frame_header(&h, hdr, ret) < 0) return AVERROR_INVALIDDATA; *duration = h.npcmblocks * DCA_PCMBLOCK_SAMPLES; *sample_rate = avpriv_dca_sample_rates[h.sr_code]; if (*profile != FF_PROFILE_UNKNOWN) return 0; *profile = FF_PROFILE_DTS; if (h.ext_audio_present) { switch (h.ext_audio_type) { case DCA_EXT_AUDIO_XCH: case DCA_EXT_AUDIO_XXCH: *profile = FF_PROFILE_DTS_ES; break; case DCA_EXT_AUDIO_X96: *profile = FF_PROFILE_DTS_96_24; break; } } frame_size = FFALIGN(h.frame_size, 4); if (buf_size - 4 < frame_size) return 0; buf += frame_size; buf_size -= frame_size; if (AV_RB32(buf) != DCA_SYNCWORD_SUBSTREAM) return 0; if (ff_dca_exss_parse(&pc1->exss, buf, buf_size) < 0) return 0; if (asset->extension_mask & DCA_EXSS_XLL) *profile = FF_PROFILE_DTS_HD_MA; else if (asset->extension_mask & (DCA_EXSS_XBR | DCA_EXSS_XXCH | DCA_EXSS_X96)) *profile = FF_PROFILE_DTS_HD_HRA; return 0; } static int dca_parse(AVCodecParserContext *s, AVCodecContext *avctx, const uint8_t **poutbuf, int *poutbuf_size, const uint8_t *buf, int buf_size) { DCAParseContext *pc1 = s->priv_data; ParseContext *pc = &pc1->pc; int next, duration, sample_rate; if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) { next = buf_size; } else { next = dca_find_frame_end(pc1, buf, buf_size); if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) { *poutbuf = NULL; *poutbuf_size = 0; return buf_size; } /* skip initial padding */ if (buf_size > pc1->startpos) { buf += pc1->startpos; buf_size -= pc1->startpos; } pc1->startpos = 0; } /* read the duration and sample rate from the frame header */ if (!dca_parse_params(pc1, buf, buf_size, &duration, &sample_rate, &avctx->profile)) { if (!avctx->sample_rate) avctx->sample_rate = sample_rate; s->duration = av_rescale(duration, avctx->sample_rate, sample_rate); } else s->duration = 0; *poutbuf = buf; *poutbuf_size = buf_size; return next; } AVCodecParser ff_dca_parser = { .codec_ids = { AV_CODEC_ID_DTS }, .priv_data_size = sizeof(DCAParseContext), .parser_init = dca_parse_init, .parser_parse = dca_parse, .parser_close = ff_parse_close, };