RTSP视频播放器客户端

/* * Copyright (C) 2011 Michael Niedermayer (michaelni@gmx.at) * Copyright (c) 2012 Justin Ruggles <justin.ruggles@gmail.com> * * This file is part of Libav. * * Libav 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. * * Libav 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 Libav; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include <stdint.h> #include "libavutil/common.h" #include "libavutil/libm.h" #include "libavutil/samplefmt.h" #include "avresample.h" #include "internal.h" #include "audio_data.h" #include "audio_mix.h" /* channel positions */ #define FRONT_LEFT 0 #define FRONT_RIGHT 1 #define FRONT_CENTER 2 #define LOW_FREQUENCY 3 #define BACK_LEFT 4 #define BACK_RIGHT 5 #define FRONT_LEFT_OF_CENTER 6 #define FRONT_RIGHT_OF_CENTER 7 #define BACK_CENTER 8 #define SIDE_LEFT 9 #define SIDE_RIGHT 10 #define TOP_CENTER 11 #define TOP_FRONT_LEFT 12 #define TOP_FRONT_CENTER 13 #define TOP_FRONT_RIGHT 14 #define TOP_BACK_LEFT 15 #define TOP_BACK_CENTER 16 #define TOP_BACK_RIGHT 17 #define STEREO_LEFT 29 #define STEREO_RIGHT 30 #define WIDE_LEFT 31 #define WIDE_RIGHT 32 #define SURROUND_DIRECT_LEFT 33 #define SURROUND_DIRECT_RIGHT 34 #define LOW_FREQUENCY_2 35 #define SQRT3_2 1.22474487139158904909 /* sqrt(3/2) */ static av_always_inline int even(uint64_t layout) { return (!layout || (layout & (layout - 1))); } static int sane_layout(uint64_t layout) { /* check that there is at least 1 front speaker */ if (!(layout & AV_CH_LAYOUT_SURROUND)) return 0; /* check for left/right symmetry */ if (!even(layout & (AV_CH_FRONT_LEFT | AV_CH_FRONT_RIGHT)) || !even(layout & (AV_CH_SIDE_LEFT | AV_CH_SIDE_RIGHT)) || !even(layout & (AV_CH_BACK_LEFT | AV_CH_BACK_RIGHT)) || !even(layout & (AV_CH_FRONT_LEFT_OF_CENTER | AV_CH_FRONT_RIGHT_OF_CENTER)) || !even(layout & (AV_CH_TOP_FRONT_LEFT | AV_CH_TOP_FRONT_RIGHT)) || !even(layout & (AV_CH_TOP_BACK_LEFT | AV_CH_TOP_BACK_RIGHT)) || !even(layout & (AV_CH_STEREO_LEFT | AV_CH_STEREO_RIGHT)) || !even(layout & (AV_CH_WIDE_LEFT | AV_CH_WIDE_RIGHT)) || !even(layout & (AV_CH_SURROUND_DIRECT_LEFT | AV_CH_SURROUND_DIRECT_RIGHT))) return 0; return 1; } int avresample_build_matrix(uint64_t in_layout, uint64_t out_layout, double center_mix_level, double surround_mix_level, double lfe_mix_level, int normalize, double *matrix_out, int stride, enum AVMatrixEncoding matrix_encoding) { int i, j, out_i, out_j; double matrix[64][64] = {{0}}; int64_t unaccounted; double maxcoef = 0; int in_channels, out_channels; if ((out_layout & AV_CH_LAYOUT_STEREO_DOWNMIX) == AV_CH_LAYOUT_STEREO_DOWNMIX) { out_layout = AV_CH_LAYOUT_STEREO; } unaccounted = in_layout & ~out_layout; in_channels = av_get_channel_layout_nb_channels( in_layout); out_channels = av_get_channel_layout_nb_channels(out_layout); memset(matrix_out, 0, out_channels * stride * sizeof(*matrix_out)); /* check if layouts are supported */ if (!in_layout || in_channels > AVRESAMPLE_MAX_CHANNELS) return AVERROR(EINVAL); if (!out_layout || out_channels > AVRESAMPLE_MAX_CHANNELS) return AVERROR(EINVAL); /* check if layouts are unbalanced or abnormal */ if (!sane_layout(in_layout) || !sane_layout(out_layout)) return AVERROR_PATCHWELCOME; /* route matching input/output channels */ for (i = 0; i < 64; i++) { if (in_layout & out_layout & (1ULL << i)) matrix[i][i] = 1.0; } /* mix front center to front left/right */ if (unaccounted & AV_CH_FRONT_CENTER) { if ((out_layout & AV_CH_LAYOUT_STEREO) == AV_CH_LAYOUT_STEREO) { matrix[FRONT_LEFT ][FRONT_CENTER] += M_SQRT1_2; matrix[FRONT_RIGHT][FRONT_CENTER] += M_SQRT1_2; } else return AVERROR_PATCHWELCOME; } /* mix front left/right to center */ if (unaccounted & AV_CH_LAYOUT_STEREO) { if (out_layout & AV_CH_FRONT_CENTER) { matrix[FRONT_CENTER][FRONT_LEFT ] += M_SQRT1_2; matrix[FRONT_CENTER][FRONT_RIGHT] += M_SQRT1_2; /* mix left/right/center to center */ if (in_layout & AV_CH_FRONT_CENTER) matrix[FRONT_CENTER][FRONT_CENTER] = center_mix_level * M_SQRT2; } else return AVERROR_PATCHWELCOME; } /* mix back center to back, side, or front */ if (unaccounted & AV_CH_BACK_CENTER) { if (out_layout & AV_CH_BACK_LEFT) { matrix[BACK_LEFT ][BACK_CENTER] += M_SQRT1_2; matrix[BACK_RIGHT][BACK_CENTER] += M_SQRT1_2; } else if (out_layout & AV_CH_SIDE_LEFT) { matrix[SIDE_LEFT ][BACK_CENTER] += M_SQRT1_2; matrix[SIDE_RIGHT][BACK_CENTER] += M_SQRT1_2; } else if (out_layout & AV_CH_FRONT_LEFT) { if (matrix_encoding == AV_MATRIX_ENCODING_DOLBY || matrix_encoding == AV_MATRIX_ENCODING_DPLII) { if (unaccounted & (AV_CH_BACK_LEFT | AV_CH_SIDE_LEFT)) { matrix[FRONT_LEFT ][BACK_CENTER] -= surround_mix_level * M_SQRT1_2; matrix[FRONT_RIGHT][BACK_CENTER] += surround_mix_level * M_SQRT1_2; } else { matrix[FRONT_LEFT ][BACK_CENTER] -= surround_mix_level; matrix[FRONT_RIGHT][BACK_CENTER] += surround_mix_level; } } else { matrix[FRONT_LEFT ][BACK_CENTER] += surround_mix_level * M_SQRT1_2; matrix[FRONT_RIGHT][BACK_CENTER] += surround_mix_level * M_SQRT1_2; } } else if (out_layout & AV_CH_FRONT_CENTER) { matrix[FRONT_CENTER][BACK_CENTER] += surround_mix_level * M_SQRT1_2; } else return AVERROR_PATCHWELCOME; } /* mix back left/right to back center, side, or front */ if (unaccounted & AV_CH_BACK_LEFT) { if (out_layout & AV_CH_BACK_CENTER) { matrix[BACK_CENTER][BACK_LEFT ] += M_SQRT1_2; matrix[BACK_CENTER][BACK_RIGHT] += M_SQRT1_2; } else if (out_layout & AV_CH_SIDE_LEFT) { /* if side channels do not exist in the input, just copy back channels to side channels, otherwise mix back into side */ if (in_layout & AV_CH_SIDE_LEFT) { matrix[SIDE_LEFT ][BACK_LEFT ] += M_SQRT1_2; matrix[SIDE_RIGHT][BACK_RIGHT] += M_SQRT1_2; } else { matrix[SIDE_LEFT ][BACK_LEFT ] += 1.0; matrix[SIDE_RIGHT][BACK_RIGHT] += 1.0; } } else if (out_layout & AV_CH_FRONT_LEFT) { if (matrix_encoding == AV_MATRIX_ENCODING_DOLBY) { matrix[FRONT_LEFT ][BACK_LEFT ] -= surround_mix_level * M_SQRT1_2; matrix[FRONT_LEFT ][BACK_RIGHT] -= surround_mix_level * M_SQRT1_2; matrix[FRONT_RIGHT][BACK_LEFT ] += surround_mix_level * M_SQRT1_2;