xref: /third_party/ffmpeg/libavcodec/8bps.c (revision cabdff1a)
1/*
2 * Quicktime Planar RGB (8BPS) Video Decoder
3 * Copyright (C) 2003 Roberto Togni
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 * QT 8BPS Video Decoder by Roberto Togni
25 * For more information about the 8BPS format, visit:
26 *   http://www.pcisys.net/~melanson/codecs/
27 *
28 * Supports: PAL8 (RGB 8bpp, paletted)
29 *         : BGR24 (RGB 24bpp) (can also output it as RGB32)
30 *         : RGB32 (RGB 32bpp, 4th plane is alpha)
31 */
32
33#include <stdio.h>
34#include <stdlib.h>
35#include <string.h>
36
37#include "libavutil/internal.h"
38#include "libavutil/intreadwrite.h"
39#include "avcodec.h"
40#include "codec_internal.h"
41#include "decode.h"
42#include "internal.h"
43
44
45static const enum AVPixelFormat pixfmt_rgb24[] = {
46    AV_PIX_FMT_BGR24, AV_PIX_FMT_0RGB32, AV_PIX_FMT_NONE };
47
48typedef struct EightBpsContext {
49    AVCodecContext *avctx;
50
51    unsigned char planes;
52    unsigned char planemap[4];
53
54    uint32_t pal[256];
55} EightBpsContext;
56
57static int decode_frame(AVCodecContext *avctx, AVFrame *frame,
58                        int *got_frame, AVPacket *avpkt)
59{
60    const uint8_t *buf = avpkt->data;
61    int buf_size       = avpkt->size;
62    EightBpsContext * const c = avctx->priv_data;
63    const unsigned char *encoded = buf;
64    unsigned char *pixptr, *pixptr_end;
65    unsigned int height = avctx->height; // Real image height
66    unsigned int dlen, p, row;
67    const unsigned char *lp, *dp, *ep;
68    unsigned char count;
69    unsigned int px_inc;
70    unsigned int planes     = c->planes;
71    unsigned char *planemap = c->planemap;
72    int ret;
73
74    if (buf_size < planes * height *2)
75        return AVERROR_INVALIDDATA;
76
77    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
78        return ret;
79
80    ep = encoded + buf_size;
81
82    /* Set data pointer after line lengths */
83    dp = encoded + planes * (height << 1);
84
85    px_inc = planes + (avctx->pix_fmt == AV_PIX_FMT_0RGB32);
86
87    for (p = 0; p < planes; p++) {
88        /* Lines length pointer for this plane */
89        lp = encoded + p * (height << 1);
90
91        /* Decode a plane */
92        for (row = 0; row < height; row++) {
93            pixptr = frame->data[0] + row * frame->linesize[0] + planemap[p];
94            pixptr_end = pixptr + frame->linesize[0];
95            if (ep - lp < row * 2 + 2)
96                return AVERROR_INVALIDDATA;
97            dlen = av_be2ne16(*(const unsigned short *)(lp + row * 2));
98            /* Decode a row of this plane */
99            while (dlen > 0) {
100                if (ep - dp <= 1)
101                    return AVERROR_INVALIDDATA;
102                if ((count = *dp++) <= 127) {
103                    count++;
104                    dlen -= count + 1;
105                    if (pixptr_end - pixptr < count * px_inc)
106                        break;
107                    if (ep - dp < count)
108                        return AVERROR_INVALIDDATA;
109                    while (count--) {
110                        *pixptr = *dp++;
111                        pixptr += px_inc;
112                    }
113                } else {
114                    count = 257 - count;
115                    if (pixptr_end - pixptr < count * px_inc)
116                        break;
117                    while (count--) {
118                        *pixptr = *dp;
119                        pixptr += px_inc;
120                    }
121                    dp++;
122                    dlen -= 2;
123                }
124            }
125        }
126    }
127
128    if (avctx->bits_per_coded_sample <= 8) {
129        frame->palette_has_changed = ff_copy_palette(c->pal, avpkt, avctx);
130
131        memcpy (frame->data[1], c->pal, AVPALETTE_SIZE);
132    }
133
134    *got_frame = 1;
135
136    /* always report that the buffer was completely consumed */
137    return buf_size;
138}
139
140static av_cold int decode_init(AVCodecContext *avctx)
141{
142    EightBpsContext * const c = avctx->priv_data;
143
144    c->avctx       = avctx;
145
146    switch (avctx->bits_per_coded_sample) {
147    case 8:
148        avctx->pix_fmt = AV_PIX_FMT_PAL8;
149        c->planes      = 1;
150        c->planemap[0] = 0; // 1st plane is palette indexes
151        break;
152    case 24:
153        avctx->pix_fmt = ff_get_format(avctx, pixfmt_rgb24);
154        c->planes      = 3;
155        c->planemap[0] = 2; // 1st plane is red
156        c->planemap[1] = 1; // 2nd plane is green
157        c->planemap[2] = 0; // 3rd plane is blue
158        break;
159    case 32:
160        avctx->pix_fmt = AV_PIX_FMT_RGB32;
161        c->planes      = 4;
162        /* handle planemap setup later for decoding rgb24 data as rbg32 */
163        break;
164    default:
165        av_log(avctx, AV_LOG_ERROR, "Error: Unsupported color depth: %u.\n",
166               avctx->bits_per_coded_sample);
167        return AVERROR_INVALIDDATA;
168    }
169
170    if (avctx->pix_fmt == AV_PIX_FMT_RGB32) {
171        c->planemap[0] = HAVE_BIGENDIAN ? 1 : 2; // 1st plane is red
172        c->planemap[1] = HAVE_BIGENDIAN ? 2 : 1; // 2nd plane is green
173        c->planemap[2] = HAVE_BIGENDIAN ? 3 : 0; // 3rd plane is blue
174        c->planemap[3] = HAVE_BIGENDIAN ? 0 : 3; // 4th plane is alpha
175    }
176    return 0;
177}
178
179const FFCodec ff_eightbps_decoder = {
180    .p.name         = "8bps",
181    .p.long_name    = NULL_IF_CONFIG_SMALL("QuickTime 8BPS video"),
182    .p.type         = AVMEDIA_TYPE_VIDEO,
183    .p.id           = AV_CODEC_ID_8BPS,
184    .priv_data_size = sizeof(EightBpsContext),
185    .init           = decode_init,
186    FF_CODEC_DECODE_CB(decode_frame),
187    .p.capabilities = AV_CODEC_CAP_DR1,
188    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE,
189};
190