FFmpeg
movsub_bsf.c
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1 /*
2  * Copyright (c) 2008 Reimar Döffinger
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 #include "libavutil/common.h"
22 #include "libavutil/intreadwrite.h"
23 #include "bsf.h"
24 #include "bsf_internal.h"
25 
27 {
28  AVPacket *in;
29  int ret = 0;
30 
31  ret = ff_bsf_get_packet(ctx, &in);
32  if (ret < 0)
33  return ret;
34 
35  if (in->size > 0xffff) {
37  goto fail;
38  }
39 
40  ret = av_new_packet(out, in->size + 2);
41  if (ret < 0) {
42  ret = AVERROR(ENOMEM);
43  goto fail;
44  }
45 
47  if (ret < 0)
48  goto fail;
49 
50  AV_WB16(out->data, in->size);
51  memcpy(out->data + 2, in->data, in->size);
52 
53 fail:
54  if (ret < 0)
56  av_packet_free(&in);
57  return ret;
58 }
59 
61  .name = "text2movsub",
62  .filter = text2movsub,
63 };
64 
66 {
67  int ret = 0;
68 
70  if (ret < 0)
71  return ret;
72 
73  if (pkt->size < 2) {
75  return AVERROR_INVALIDDATA;
76  }
77 
78  pkt->size = FFMIN(pkt->size - 2, AV_RB16(pkt->data));
79  pkt->data += 2;
80 
81  return 0;
82 }
83 
85  .name = "mov2textsub",
86  .filter = mov2textsub,
87 };
av_packet_unref
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
Definition: avpacket.c:417
AVERROR
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
bsf_internal.h
out
FILE * out
Definition: movenc.c:54
AVBitStreamFilter::name
const char * name
Definition: bsf.h:91
AVPacket::data
uint8_t * data
Definition: packet.h:373
ff_bsf_get_packet
int ff_bsf_get_packet(AVBSFContext *ctx, AVPacket **pkt)
Called by the bitstream filters to get the next packet for filtering.
Definition: bsf.c:231
av_packet_free
void av_packet_free(AVPacket **pkt)
Free the packet, if the packet is reference counted, it will be unreferenced first.
Definition: avpacket.c:75
AVBSFContext
The bitstream filter state.
Definition: bsf.h:47
bsf.h
fail
#define fail()
Definition: checkasm.h:127
ff_text2movsub_bsf
const AVBitStreamFilter ff_text2movsub_bsf
Definition: movsub_bsf.c:60
pkt
AVPacket * pkt
Definition: movenc.c:59
intreadwrite.h
av_new_packet
int av_new_packet(AVPacket *pkt, int size)
Allocate the payload of a packet and initialize its fields with default values.
Definition: avpacket.c:99
text2movsub
static int text2movsub(AVBSFContext *ctx, AVPacket *out)
Definition: movsub_bsf.c:26
ctx
AVFormatContext * ctx
Definition: movenc.c:48
AV_WB16
#define AV_WB16(p, v)
Definition: intreadwrite.h:405
mov2textsub
static int mov2textsub(AVBSFContext *ctx, AVPacket *pkt)
Definition: movsub_bsf.c:65
AVPacket::size
int size
Definition: packet.h:374
av_packet_copy_props
int av_packet_copy_props(AVPacket *dst, const AVPacket *src)
Copy only "properties" fields from src to dst.
Definition: avpacket.c:380
common.h
FFMIN
#define FFMIN(a, b)
Definition: macros.h:49
ret
ret
Definition: filter_design.txt:187
AVBitStreamFilter
Definition: bsf.h:90
AVPacket
This structure stores compressed data.
Definition: packet.h:350
ff_mov2textsub_bsf
const AVBitStreamFilter ff_mov2textsub_bsf
Definition: movsub_bsf.c:84
ff_bsf_get_packet_ref
int ff_bsf_get_packet_ref(AVBSFContext *ctx, AVPacket *pkt)
Called by bitstream filters to get packet for filtering.
Definition: bsf.c:252
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
AV_RB16
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_WB32 unsigned int_TMPL AV_WB24 unsigned int_TMPL AV_RB16
Definition: bytestream.h:98