1/*
2 * HAPQA extract bitstream filter
3 * Copyright (c) 2017 Jokyo Images
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22/**
23 * @file
24 * HAPQA extract bitstream filter
25 * extract one of the two textures of the HAQA
26 */
27
28#include "bsf.h"
29#include "bsf_internal.h"
30#include "bytestream.h"
31#include "hap.h"
32
33typedef struct HapqaExtractContext {
34    const AVClass *class;
35    int texture;/* index of the texture to keep (0 for rgb or 1 for alpha) */
36} HapqaExtractContext;
37
38static int check_texture(HapqaExtractContext *ctx, int section_type) {
39    if (((ctx->texture == 0)&&((section_type & 0x0F) == 0x0F)) || /* HapQ texture and rgb extract */
40        ((ctx->texture == 1)&&((section_type & 0x0F) == 0x01))) /* HapAlphaOnly texture and alpha extract */
41    {
42        return 1; /* the texture is the one to keep */
43    } else {
44        return 0;
45    }
46}
47
48static int hapqa_extract(AVBSFContext *bsf, AVPacket *pkt)
49{
50    HapqaExtractContext *ctx = bsf->priv_data;
51    GetByteContext gbc;
52    int section_size;
53    enum HapSectionType section_type;
54    int start_section_size;
55    int target_packet_size = 0;
56    int ret = 0;
57
58    ret = ff_bsf_get_packet_ref(bsf, pkt);
59    if (ret < 0)
60        return ret;
61
62    bytestream2_init(&gbc, pkt->data, pkt->size);
63    ret = ff_hap_parse_section_header(&gbc, &section_size, &section_type);
64    if (ret != 0)
65        goto fail;
66
67    if ((section_type & 0x0F) != 0x0D) {
68        av_log(bsf, AV_LOG_ERROR, "Invalid section type for HAPQA %#04x.\n", section_type & 0x0F);
69        ret = AVERROR_INVALIDDATA;
70        goto fail;
71    }
72
73    start_section_size = 4;
74
75    bytestream2_seek(&gbc, start_section_size, SEEK_SET);/* go to start of the first texture */
76
77    ret = ff_hap_parse_section_header(&gbc, &section_size, &section_type);
78    if (ret != 0)
79        goto fail;
80
81    target_packet_size = section_size + 4;
82
83    if (check_texture(ctx, section_type) == 0) { /* the texture is not the one to keep */
84        start_section_size += 4 + section_size;
85        bytestream2_seek(&gbc, start_section_size, SEEK_SET);/* go to start of the second texture */
86        ret = ff_hap_parse_section_header(&gbc, &section_size, &section_type);
87        if (ret != 0)
88            goto fail;
89
90        target_packet_size = section_size + 4;
91
92        if (check_texture(ctx, section_type) == 0){ /* the second texture is not the one to keep */
93            av_log(bsf, AV_LOG_ERROR, "No valid texture found.\n");
94            ret = AVERROR_INVALIDDATA;
95            goto fail;
96        }
97    }
98
99    pkt->data += start_section_size;
100    pkt->size = target_packet_size;
101
102fail:
103    if (ret < 0)
104        av_packet_unref(pkt);
105    return ret;
106}
107
108static const enum AVCodecID codec_ids[] = {
109    AV_CODEC_ID_HAP, AV_CODEC_ID_NONE,
110};
111
112#define OFFSET(x) offsetof(HapqaExtractContext, x)
113#define FLAGS (AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_BSF_PARAM)
114static const AVOption options[] = {
115    { "texture", "texture to keep", OFFSET(texture), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, FLAGS, "texture" },
116        { "color", "keep HapQ texture",         0, AV_OPT_TYPE_CONST, { .i64 = 0 }, 0, 0, FLAGS, "texture" },
117        { "alpha", "keep HapAlphaOnly texture", 0, AV_OPT_TYPE_CONST, { .i64 = 1 }, 0, 0, FLAGS, "texture" },
118    { NULL },
119};
120
121static const AVClass hapqa_extract_class = {
122    .class_name = "hapqa_extract_bsf",
123    .item_name  = av_default_item_name,
124    .option     = options,
125    .version    = LIBAVUTIL_VERSION_INT,
126};
127
128const FFBitStreamFilter ff_hapqa_extract_bsf = {
129    .p.name         = "hapqa_extract",
130    .p.codec_ids    = codec_ids,
131    .p.priv_class   = &hapqa_extract_class,
132    .priv_data_size = sizeof(HapqaExtractContext),
133    .filter         = hapqa_extract,
134};
135