/
githubmirror
/
FFmpeg
Обзор
Документация
Войти
/
githubmirror
/
FFmpeg
Код
Запросы
0
Пакеты
0
Релизы
0
Аналитика
Безопасность
n3.4.14
libavformat/avc.c
210 строк
6 KB
Clément Bœsch
Merge commit '41ed7ab45fc693f7d7fc35664c0233f4c32d69bb'
21 июн 2016, 22:55
21 июн 2016, 22:55
8ef57a0
Код
Авторство
О чём код?
/* * AVC helper functions for muxers * Copyright (c) 2006 Baptiste Coudurier <baptiste.coudurier@smartjog.com> * * 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/intreadwrite.h" #include "avformat.h" #include "avio.h" #include "avc.h" static const uint8_t *ff_avc_find_startcode_internal(const uint8_t *p, const uint8_t *end) { const uint8_t *a = p + 4 - ((intptr_t)p & 3); for (end -= 3; p < a && p < end; p++) { if (p[0] == 0 && p[1] == 0 && p[2] == 1) return p; } for (end -= 3; p < end; p += 4) { uint32_t x = *(const uint32_t*)p; // if ((x - 0x01000100) & (~x) & 0x80008000) // little endian // if ((x - 0x00010001) & (~x) & 0x00800080) // big endian if ((x - 0x01010101) & (~x) & 0x80808080) { // generic if (p[1] == 0) { if (p[0] == 0 && p[2] == 1) return p; if (p[2] == 0 && p[3] == 1) return p+1; } if (p[3] == 0) { if (p[2] == 0 && p[4] == 1) return p+2; if (p[4] == 0 && p[5] == 1) return p+3; } } } for (end += 3; p < end; p++) { if (p[0] == 0 && p[1] == 0 && p[2] == 1) return p; } return end + 3; } const uint8_t *ff_avc_find_startcode(const uint8_t *p, const uint8_t *end){ const uint8_t *out= ff_avc_find_startcode_internal(p, end); if(p<out && out<end && !out[-1]) out--; return out; } int ff_avc_parse_nal_units(AVIOContext *pb, const uint8_t *buf_in, int size) { const uint8_t *p = buf_in; const uint8_t *end = p + size; const uint8_t *nal_start, *nal_end; size = 0; nal_start = ff_avc_find_startcode(p, end); for (;;) { while (nal_start < end && !*(nal_start++)); if (nal_start == end) break; nal_end = ff_avc_find_startcode(nal_start, end); avio_wb32(pb, nal_end - nal_start); avio_write(pb, nal_start, nal_end - nal_start); size += 4 + nal_end - nal_start; nal_start = nal_end; } return size; } int ff_avc_parse_nal_units_buf(const uint8_t *buf_in, uint8_t **buf, int *size) { AVIOContext *pb; int ret = avio_open_dyn_buf(&pb); if(ret < 0) return ret; ff_avc_parse_nal_units(pb, buf_in, *size); av_freep(buf); *size = avio_close_dyn_buf(pb, buf); return 0; } int ff_isom_write_avcc(AVIOContext *pb, const uint8_t *data, int len) { if (len > 6) { /* check for H.264 start code */ if (AV_RB32(data) == 0x00000001 || AV_RB24(data) == 0x000001) { uint8_t *buf=NULL, *end, *start; uint32_t sps_size=0, pps_size=0; uint8_t *sps=0, *pps=0; int ret = ff_avc_parse_nal_units_buf(data, &buf, &len); if (ret < 0) return ret; start = buf; end = buf + len; /* look for sps and pps */ while (end - buf > 4) { uint32_t size; uint8_t nal_type; size = FFMIN(AV_RB32(buf), end - buf - 4); buf += 4; nal_type = buf[0] & 0x1f; if (nal_type == 7) { /* SPS */ sps = buf; sps_size = size; } else if (nal_type == 8) { /* PPS */ pps = buf; pps_size = size; } buf += size; } if (!sps || !pps || sps_size < 4 || sps_size > UINT16_MAX || pps_size > UINT16_MAX) return AVERROR_INVALIDDATA; avio_w8(pb, 1); /* version */ avio_w8(pb, sps[1]); /* profile */ avio_w8(pb, sps[2]); /* profile compat */ avio_w8(pb, sps[3]); /* level */ avio_w8(pb, 0xff); /* 6 bits reserved (111111) + 2 bits nal size length - 1 (11) */ avio_w8(pb, 0xe1); /* 3 bits reserved (111) + 5 bits number of sps (00001) */ avio_wb16(pb, sps_size); avio_write(pb, sps, sps_size); avio_w8(pb, 1); /* number of pps */ avio_wb16(pb, pps_size); avio_write(pb, pps, pps_size); av_free(start); } else { avio_write(pb, data, len); } } return 0; } int ff_avc_write_annexb_extradata(const uint8_t *in, uint8_t **buf, int *size) { uint16_t sps_size, pps_size; uint8_t *out; int out_size; *buf = NULL; if (*size >= 4 && (AV_RB32(in) == 0x00000001 || AV_RB24(in) == 0x000001)) return 0; if (*size < 11 || in[0] != 1) return AVERROR_INVALIDDATA; sps_size = AV_RB16(&in[6]); if (11 + sps_size > *size) return AVERROR_INVALIDDATA; pps_size = AV_RB16(&in[9 + sps_size]); if (11 + sps_size + pps_size > *size) return AVERROR_INVALIDDATA; out_size = 8 + sps_size + pps_size; out = av_mallocz(out_size + AV_INPUT_BUFFER_PADDING_SIZE); if (!out) return AVERROR(ENOMEM); AV_WB32(&out[0], 0x00000001); memcpy(out + 4, &in[8], sps_size); AV_WB32(&out[4 + sps_size], 0x00000001); memcpy(out + 8 + sps_size, &in[11 + sps_size], pps_size); *buf = out; *size = out_size; return 0; } const uint8_t *ff_avc_mp4_find_startcode(const uint8_t *start, const uint8_t *end, int nal_length_size) { unsigned int res = 0; if (end - start < nal_length_size) return NULL; while (nal_length_size--) res = (res << 8) | *start++; if (res > end - start) return NULL; return start + res; }