lavc: add a new bitstream filtering API
[libav.git] / libavcodec / movsub_bsf.c
1 /*
2 * Copyright (c) 2008 Reimar Döffinger
3 *
4 * This file is part of Libav.
5 *
6 * Libav 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 * Libav 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 Libav; 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 "avcodec.h"
24 #include "bsf.h"
25
26 static int text2movsub(AVBSFContext *ctx, AVPacket *out)
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) {
36 ret = AVERROR_INVALIDDATA;
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
46 ret = av_packet_copy_props(out, in);
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)
55 av_packet_unref(out);
56 av_packet_free(&in);
57 return ret;
58 }
59
60 const AVBitStreamFilter ff_text2movsub_bsf = {
61 .name = "text2movsub",
62 .filter = text2movsub,
63 };
64
65 static int mov2textsub(AVBSFContext *ctx, AVPacket *out)
66 {
67 AVPacket *in;
68 int ret = 0;
69
70 ret = ff_bsf_get_packet(ctx, &in);
71 if (ret < 0)
72 return ret;
73
74 if (in->size < 2) {
75 ret = AVERROR_INVALIDDATA;
76 goto fail;
77 }
78
79 ret = av_new_packet(out, FFMIN(in->size - 2, AV_RB16(in->data)));
80 if (ret < 0)
81 goto fail;
82
83 ret = av_packet_copy_props(out, in);
84 if (ret < 0)
85 goto fail;
86
87 memcpy(out->data, in->data + 2, out->size);
88
89 fail:
90 if (ret < 0)
91 av_packet_unref(out);
92 av_packet_free(&in);
93 return ret;
94 }
95
96 const AVBitStreamFilter ff_mov2textsub_bsf = {
97 .name = "mov2textsub",
98 .filter = mov2textsub,
99 };