yading@10: /*
yading@10:  * TAK parser
yading@10:  * Copyright (c) 2012 Michael Niedermayer
yading@10:  *
yading@10:  * This file is part of FFmpeg.
yading@10:  *
yading@10:  * FFmpeg is free software; you can redistribute it and/or
yading@10:  * modify it under the terms of the GNU Lesser General Public
yading@10:  * License as published by the Free Software Foundation; either
yading@10:  * version 2.1 of the License, or (at your option) any later version.
yading@10:  *
yading@10:  * FFmpeg is distributed in the hope that it will be useful,
yading@10:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@10:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@10:  * Lesser General Public License for more details.
yading@10:  *
yading@10:  * You should have received a copy of the GNU Lesser General Public
yading@10:  * License along with FFmpeg; if not, write to the Free Software
yading@10:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@10:  */
yading@10: 
yading@10: /**
yading@10:  * @file
yading@10:  * TAK parser
yading@10:  **/
yading@10: 
yading@10: #include "tak.h"
yading@10: #include "parser.h"
yading@10: 
yading@10: typedef struct TAKParseContext {
yading@10:     ParseContext  pc;
yading@10:     TAKStreamInfo ti;
yading@10:     int           index;
yading@10: } TAKParseContext;
yading@10: 
yading@10: static av_cold int tak_init(AVCodecParserContext *s)
yading@10: {
yading@10:     ff_tak_init_crc();
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static int tak_parse(AVCodecParserContext *s, AVCodecContext *avctx,
yading@10:                      const uint8_t **poutbuf, int *poutbuf_size,
yading@10:                      const uint8_t *buf, int buf_size)
yading@10: {
yading@10:     TAKParseContext *t = s->priv_data;
yading@10:     ParseContext *pc   = &t->pc;
yading@10:     int next           = END_NOT_FOUND;
yading@10:     GetBitContext gb;
yading@10:     int consumed = 0;
yading@10:     int needed   = buf_size ? TAK_MAX_FRAME_HEADER_BYTES : 8;
yading@10: 
yading@10:     if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
yading@10:         TAKStreamInfo ti;
yading@10:         init_get_bits(&gb, buf, buf_size);
yading@10:         if (!ff_tak_decode_frame_header(avctx, &gb, &ti, 127))
yading@10:             s->duration = t->ti.last_frame_samples ? t->ti.last_frame_samples
yading@10:                                                    : t->ti.frame_samples;
yading@10:         *poutbuf      = buf;
yading@10:         *poutbuf_size = buf_size;
yading@10:         return buf_size;
yading@10:     }
yading@10: 
yading@10:     while (buf_size || t->index + needed <= pc->index) {
yading@10:         if (buf_size && t->index + TAK_MAX_FRAME_HEADER_BYTES > pc->index) {
yading@10:             int tmp_buf_size       = FFMIN(2 * TAK_MAX_FRAME_HEADER_BYTES,
yading@10:                                            buf_size);
yading@10:             const uint8_t *tmp_buf = buf;
yading@10: 
yading@10:             if (ff_combine_frame(pc, END_NOT_FOUND, &tmp_buf, &tmp_buf_size) != -1)
yading@10:                 return AVERROR(ENOMEM);
yading@10:             consumed += tmp_buf_size;
yading@10:             buf      += tmp_buf_size;
yading@10:             buf_size -= tmp_buf_size;
yading@10:         }
yading@10: 
yading@10:         for (; t->index + needed <= pc->index; t->index++) {
yading@10:             if (pc->buffer[ t->index     ] == 0xFF &&
yading@10:                 pc->buffer[ t->index + 1 ] == 0xA0) {
yading@10:                 TAKStreamInfo ti;
yading@10: 
yading@10:                 init_get_bits(&gb, pc->buffer + t->index,
yading@10:                               8 * (pc->index - t->index));
yading@10:                 if (!ff_tak_decode_frame_header(avctx, &gb,
yading@10:                         pc->frame_start_found ? &ti : &t->ti, 127) &&
yading@10:                     !ff_tak_check_crc(pc->buffer + t->index,
yading@10:                                       get_bits_count(&gb) / 8)) {
yading@10:                     if (!pc->frame_start_found) {
yading@10:                         pc->frame_start_found = 1;
yading@10:                         s->duration           = t->ti.last_frame_samples ?
yading@10:                                                 t->ti.last_frame_samples :
yading@10:                                                 t->ti.frame_samples;
yading@10:                     } else {
yading@10:                         pc->frame_start_found = 0;
yading@10:                         next                  = t->index - pc->index;
yading@10:                         t->index              = 0;
yading@10:                         goto found;
yading@10:                     }
yading@10:                 }
yading@10:             }
yading@10:         }
yading@10:     }
yading@10: found:
yading@10: 
yading@10:     if (consumed && !buf_size && next == END_NOT_FOUND ||
yading@10:         ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
yading@10:         *poutbuf      = NULL;
yading@10:         *poutbuf_size = 0;
yading@10:         return buf_size + consumed;
yading@10:     }
yading@10: 
yading@10:     if (next != END_NOT_FOUND) {
yading@10:         next        += consumed;
yading@10:         pc->overread = FFMAX(0, -next);
yading@10:     }
yading@10: 
yading@10:     *poutbuf      = buf;
yading@10:     *poutbuf_size = buf_size;
yading@10:     return next;
yading@10: }
yading@10: 
yading@10: AVCodecParser ff_tak_parser = {
yading@10:     .codec_ids      = { AV_CODEC_ID_TAK },
yading@10:     .priv_data_size = sizeof(TAKParseContext),
yading@10:     .parser_init    = tak_init,
yading@10:     .parser_parse   = tak_parse,
yading@10:     .parser_close   = ff_parse_close,
yading@10: };