third_party_ffmpeg/libavcodec/avpacket.c
Reimar Döffinger feb993e579 Add av_shrink_packet function for use in av_get_packet that reduces pkt->size
and ensures the following padding is correctly initialized to 0.

Originally committed as revision 18378 to svn://svn.ffmpeg.org/ffmpeg/trunk
2009-04-08 20:19:12 +00:00

90 lines
2.6 KiB
C

/*
* AVPacket functions for libavcodec
* Copyright (c) 2000, 2001, 2002 Fabrice Bellard
*
* 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 "avcodec.h"
void av_destruct_packet_nofree(AVPacket *pkt)
{
pkt->data = NULL; pkt->size = 0;
}
void av_destruct_packet(AVPacket *pkt)
{
av_free(pkt->data);
pkt->data = NULL; pkt->size = 0;
}
void av_init_packet(AVPacket *pkt)
{
pkt->pts = AV_NOPTS_VALUE;
pkt->dts = AV_NOPTS_VALUE;
pkt->pos = -1;
pkt->duration = 0;
pkt->convergence_duration = 0;
pkt->flags = 0;
pkt->stream_index = 0;
pkt->destruct= av_destruct_packet_nofree;
}
int av_new_packet(AVPacket *pkt, int size)
{
uint8_t *data;
if((unsigned)size > (unsigned)size + FF_INPUT_BUFFER_PADDING_SIZE)
return AVERROR(ENOMEM);
data = av_malloc(size + FF_INPUT_BUFFER_PADDING_SIZE);
if (!data)
return AVERROR(ENOMEM);
memset(data + size, 0, FF_INPUT_BUFFER_PADDING_SIZE);
av_init_packet(pkt);
pkt->data = data;
pkt->size = size;
pkt->destruct = av_destruct_packet;
return 0;
}
void av_shrink_packet(AVPacket *pkt, int size)
{
if (pkt->size <= size) return;
pkt->size = size;
memset(pkt->data + size, 0, FF_INPUT_BUFFER_PADDING_SIZE);
}
int av_dup_packet(AVPacket *pkt)
{
if (((pkt->destruct == av_destruct_packet_nofree) || (pkt->destruct == NULL)) && pkt->data) {
uint8_t *data;
/* We duplicate the packet and don't forget to add the padding again. */
if((unsigned)pkt->size > (unsigned)pkt->size + FF_INPUT_BUFFER_PADDING_SIZE)
return AVERROR(ENOMEM);
data = av_malloc(pkt->size + FF_INPUT_BUFFER_PADDING_SIZE);
if (!data) {
return AVERROR(ENOMEM);
}
memcpy(data, pkt->data, pkt->size);
memset(data + pkt->size, 0, FF_INPUT_BUFFER_PADDING_SIZE);
pkt->data = data;
pkt->destruct = av_destruct_packet;
}
return 0;
}