/libavcodec/8bps.c

  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 "internal.h"
 41
 42
 43static const enum AVPixelFormat pixfmt_rgb24[] = {
 44    AV_PIX_FMT_BGR24, AV_PIX_FMT_0RGB32, AV_PIX_FMT_NONE };
 45
 46typedef struct EightBpsContext {
 47    AVCodecContext *avctx;
 48
 49    unsigned char planes;
 50    unsigned char planemap[4];
 51
 52    uint32_t pal[256];
 53} EightBpsContext;
 54
 55static int decode_frame(AVCodecContext *avctx, void *data,
 56                        int *got_frame, AVPacket *avpkt)
 57{
 58    AVFrame *frame = data;
 59    const uint8_t *buf = avpkt->data;
 60    int buf_size       = avpkt->size;
 61    EightBpsContext * const c = avctx->priv_data;
 62    const unsigned char *encoded = buf;
 63    unsigned char *pixptr, *pixptr_end;
 64    unsigned int height = avctx->height; // Real image height
 65    unsigned int dlen, p, row;
 66    const unsigned char *lp, *dp, *ep;
 67    unsigned char count;
 68    unsigned int px_inc;
 69    unsigned int planes     = c->planes;
 70    unsigned char *planemap = c->planemap;
 71    int ret;
 72
 73    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
 74        return ret;
 75
 76    ep = encoded + buf_size;
 77
 78    /* Set data pointer after line lengths */
 79    dp = encoded + planes * (height << 1);
 80
 81    px_inc = planes + (avctx->pix_fmt == AV_PIX_FMT_0RGB32);
 82
 83    for (p = 0; p < planes; p++) {
 84        /* Lines length pointer for this plane */
 85        lp = encoded + p * (height << 1);
 86
 87        /* Decode a plane */
 88        for (row = 0; row < height; row++) {
 89            pixptr = frame->data[0] + row * frame->linesize[0] + planemap[p];
 90            pixptr_end = pixptr + frame->linesize[0];
 91            if (ep - lp < row * 2 + 2)
 92                return AVERROR_INVALIDDATA;
 93            dlen = av_be2ne16(*(const unsigned short *)(lp + row * 2));
 94            /* Decode a row of this plane */
 95            while (dlen > 0) {
 96                if (ep - dp <= 1)
 97                    return AVERROR_INVALIDDATA;
 98                if ((count = *dp++) <= 127) {
 99                    count++;
100                    dlen -= count + 1;
101                    if (pixptr_end - pixptr < count * px_inc)
102                        break;
103                    if (ep - dp < count)
104                        return AVERROR_INVALIDDATA;
105                    while (count--) {
106                        *pixptr = *dp++;
107                        pixptr += px_inc;
108                    }
109                } else {
110                    count = 257 - count;
111                    if (pixptr_end - pixptr < count * px_inc)
112                        break;
113                    while (count--) {
114                        *pixptr = *dp;
115                        pixptr += px_inc;
116                    }
117                    dp++;
118                    dlen -= 2;
119                }
120            }
121        }
122    }
123
124    if (avctx->bits_per_coded_sample <= 8) {
125        int size;
126        const uint8_t *pal = av_packet_get_side_data(avpkt,
127                                                     AV_PKT_DATA_PALETTE,
128                                                     &size);
129        if (pal && size == AVPALETTE_SIZE) {
130            frame->palette_has_changed = 1;
131            memcpy(c->pal, pal, AVPALETTE_SIZE);
132        } else if (pal) {
133            av_log(avctx, AV_LOG_ERROR, "Palette size %d is wrong\n", size);
134        }
135
136        memcpy (frame->data[1], c->pal, AVPALETTE_SIZE);
137    }
138
139    *got_frame = 1;
140
141    /* always report that the buffer was completely consumed */
142    return buf_size;
143}
144
145static av_cold int decode_init(AVCodecContext *avctx)
146{
147    EightBpsContext * const c = avctx->priv_data;
148
149    c->avctx       = avctx;
150
151    switch (avctx->bits_per_coded_sample) {
152    case 8:
153        avctx->pix_fmt = AV_PIX_FMT_PAL8;
154        c->planes      = 1;
155        c->planemap[0] = 0; // 1st plane is palette indexes
156        break;
157    case 24:
158        avctx->pix_fmt = ff_get_format(avctx, pixfmt_rgb24);
159        c->planes      = 3;
160        c->planemap[0] = 2; // 1st plane is red
161        c->planemap[1] = 1; // 2nd plane is green
162        c->planemap[2] = 0; // 3rd plane is blue
163        break;
164    case 32:
165        avctx->pix_fmt = AV_PIX_FMT_RGB32;
166        c->planes      = 4;
167        /* handle planemap setup later for decoding rgb24 data as rbg32 */
168        break;
169    default:
170        av_log(avctx, AV_LOG_ERROR, "Error: Unsupported color depth: %u.\n",
171               avctx->bits_per_coded_sample);
172        return AVERROR_INVALIDDATA;
173    }
174
175    if (avctx->pix_fmt == AV_PIX_FMT_RGB32) {
176        c->planemap[0] = HAVE_BIGENDIAN ? 1 : 2; // 1st plane is red
177        c->planemap[1] = HAVE_BIGENDIAN ? 2 : 1; // 2nd plane is green
178        c->planemap[2] = HAVE_BIGENDIAN ? 3 : 0; // 3rd plane is blue
179        c->planemap[3] = HAVE_BIGENDIAN ? 0 : 3; // 4th plane is alpha
180    }
181    return 0;
182}
183
184AVCodec ff_eightbps_decoder = {
185    .name           = "8bps",
186    .long_name      = NULL_IF_CONFIG_SMALL("QuickTime 8BPS video"),
187    .type           = AVMEDIA_TYPE_VIDEO,
188    .id             = AV_CODEC_ID_8BPS,
189    .priv_data_size = sizeof(EightBpsContext),
190    .init           = decode_init,
191    .decode         = decode_frame,
192    .capabilities   = AV_CODEC_CAP_DR1,
193};