mpeg4audio_copy_pce.h (2579B)
1 /* 2 * MPEG-4 Audio PCE copying function 3 * 4 * This file is part of FFmpeg. 5 * 6 * FFmpeg is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU Lesser General Public 8 * License as published by the Free Software Foundation; either 9 * version 2.1 of the License, or (at your option) any later version. 10 * 11 * FFmpeg is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 * Lesser General Public License for more details. 15 * 16 * You should have received a copy of the GNU Lesser General Public 17 * License along with FFmpeg; if not, write to the Free Software 18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 19 */ 20 21 #ifndef AVCODEC_MPEG4AUDIO_COPY_PCE_H 22 #define AVCODEC_MPEG4AUDIO_COPY_PCE_H 23 24 #include "libavutil/attributes.h" 25 26 #include "get_bits.h" 27 #include "put_bits.h" 28 29 static av_always_inline unsigned int ff_pce_copy_bits(PutBitContext *pb, 30 GetBitContext *gb, 31 int bits) 32 { 33 unsigned int el = get_bits(gb, bits); 34 put_bits(pb, bits, el); 35 return el; 36 } 37 38 static inline int ff_copy_pce_data(PutBitContext *pb, GetBitContext *gb) 39 { 40 int five_bit_ch, four_bit_ch, comment_size, bits; 41 int offset = put_bits_count(pb); 42 43 ff_pce_copy_bits(pb, gb, 10); // Tag, Object Type, Frequency 44 five_bit_ch = ff_pce_copy_bits(pb, gb, 4); // Front 45 five_bit_ch += ff_pce_copy_bits(pb, gb, 4); // Side 46 five_bit_ch += ff_pce_copy_bits(pb, gb, 4); // Back 47 four_bit_ch = ff_pce_copy_bits(pb, gb, 2); // LFE 48 four_bit_ch += ff_pce_copy_bits(pb, gb, 3); // Data 49 five_bit_ch += ff_pce_copy_bits(pb, gb, 4); // Coupling 50 if (ff_pce_copy_bits(pb, gb, 1)) // Mono Mixdown 51 ff_pce_copy_bits(pb, gb, 4); 52 if (ff_pce_copy_bits(pb, gb, 1)) // Stereo Mixdown 53 ff_pce_copy_bits(pb, gb, 4); 54 if (ff_pce_copy_bits(pb, gb, 1)) // Matrix Mixdown 55 ff_pce_copy_bits(pb, gb, 3); 56 for (bits = five_bit_ch*5+four_bit_ch*4; bits > 16; bits -= 16) 57 ff_pce_copy_bits(pb, gb, 16); 58 if (bits) 59 ff_pce_copy_bits(pb, gb, bits); 60 align_put_bits(pb); 61 align_get_bits(gb); 62 comment_size = ff_pce_copy_bits(pb, gb, 8); 63 for (; comment_size > 0; comment_size--) 64 ff_pce_copy_bits(pb, gb, 8); 65 66 return put_bits_count(pb) - offset; 67 } 68 69 #endif /* AVCODEC_MPEG4AUDIO_COPY_PCE_H */