Libav
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00001 /* 00002 * AVPacket functions for libavcodec 00003 * Copyright (c) 2000, 2001, 2002 Fabrice Bellard 00004 * 00005 * This file is part of FFmpeg. 00006 * 00007 * FFmpeg is free software; you can redistribute it and/or 00008 * modify it under the terms of the GNU Lesser General Public 00009 * License as published by the Free Software Foundation; either 00010 * version 2.1 of the License, or (at your option) any later version. 00011 * 00012 * FFmpeg is distributed in the hope that it will be useful, 00013 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00015 * Lesser General Public License for more details. 00016 * 00017 * You should have received a copy of the GNU Lesser General Public 00018 * License along with FFmpeg; if not, write to the Free Software 00019 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 00020 */ 00021 00022 #include "avcodec.h" 00023 00024 00025 void av_destruct_packet_nofree(AVPacket *pkt) 00026 { 00027 pkt->data = NULL; pkt->size = 0; 00028 } 00029 00030 void av_destruct_packet(AVPacket *pkt) 00031 { 00032 av_free(pkt->data); 00033 pkt->data = NULL; pkt->size = 0; 00034 } 00035 00036 void av_init_packet(AVPacket *pkt) 00037 { 00038 pkt->pts = AV_NOPTS_VALUE; 00039 pkt->dts = AV_NOPTS_VALUE; 00040 pkt->pos = -1; 00041 pkt->duration = 0; 00042 pkt->convergence_duration = 0; 00043 pkt->flags = 0; 00044 pkt->stream_index = 0; 00045 pkt->destruct= NULL; 00046 } 00047 00048 int av_new_packet(AVPacket *pkt, int size) 00049 { 00050 uint8_t *data= NULL; 00051 if((unsigned)size < (unsigned)size + FF_INPUT_BUFFER_PADDING_SIZE) 00052 data = av_malloc(size + FF_INPUT_BUFFER_PADDING_SIZE); 00053 if (data){ 00054 memset(data + size, 0, FF_INPUT_BUFFER_PADDING_SIZE); 00055 }else 00056 size=0; 00057 00058 av_init_packet(pkt); 00059 pkt->data = data; 00060 pkt->size = size; 00061 pkt->destruct = av_destruct_packet; 00062 if(!data) 00063 return AVERROR(ENOMEM); 00064 return 0; 00065 } 00066 00067 void av_shrink_packet(AVPacket *pkt, int size) 00068 { 00069 if (pkt->size <= size) return; 00070 pkt->size = size; 00071 memset(pkt->data + size, 0, FF_INPUT_BUFFER_PADDING_SIZE); 00072 } 00073 00074 int av_dup_packet(AVPacket *pkt) 00075 { 00076 if (((pkt->destruct == av_destruct_packet_nofree) || (pkt->destruct == NULL)) && pkt->data) { 00077 uint8_t *data; 00078 /* We duplicate the packet and don't forget to add the padding again. */ 00079 if((unsigned)pkt->size > (unsigned)pkt->size + FF_INPUT_BUFFER_PADDING_SIZE) 00080 return AVERROR(ENOMEM); 00081 data = av_malloc(pkt->size + FF_INPUT_BUFFER_PADDING_SIZE); 00082 if (!data) { 00083 return AVERROR(ENOMEM); 00084 } 00085 memcpy(data, pkt->data, pkt->size); 00086 memset(data + pkt->size, 0, FF_INPUT_BUFFER_PADDING_SIZE); 00087 pkt->data = data; 00088 pkt->destruct = av_destruct_packet; 00089 } 00090 return 0; 00091 } 00092 00093 void av_free_packet(AVPacket *pkt) 00094 { 00095 if (pkt) { 00096 if (pkt->destruct) pkt->destruct(pkt); 00097 pkt->data = NULL; pkt->size = 0; 00098 } 00099 }