tscc.c 5.58 KB
Newer Older
1 2 3 4
/*
 * TechSmith Camtasia decoder
 * Copyright (c) 2004 Konstantin Shishkov
 *
5 6 7
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
8 9
 * modify it under the terms of the GNU Lesser General Public
 * 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 14 15 16 17
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * 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 25 26 27 28 29 30 31 32 33
 * TechSmith Camtasia decoder
 *
 * Fourcc: TSCC
 *
 * Codec is very simple:
 *  it codes picture (picture difference, really)
 *  with algorithm almost identical to Windows RLE8,
 *  only without padding and with greater pixel sizes,
 *  then this coded picture is packed with ZLib
 *
Mike Melanson's avatar
Mike Melanson committed
34
 * Supports: BGR8,BGR555,BGR24 - only BGR8 and BGR555 tested
35 36 37 38 39 40 41
 *
 */

#include <stdio.h>
#include <stdlib.h>

#include "avcodec.h"
42
#include "internal.h"
43
#include "msrledec.h"
44 45 46 47 48 49

#include <zlib.h>

typedef struct TsccContext {

    AVCodecContext *avctx;
50
    AVFrame *frame;
51 52 53 54 55 56 57

    // Bits per pixel
    int bpp;
    // Decompressed data size
    unsigned int decomp_size;
    // Decompression buffer
    unsigned char* decomp_buf;
58
    GetByteContext gb;
59 60
    int height;
    z_stream zstream;
61 62

    uint32_t pal[256];
63 64
} CamtasiaContext;

65 66
static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
                        AVPacket *avpkt)
67
{
68 69
    const uint8_t *buf = avpkt->data;
    int buf_size = avpkt->size;
70
    CamtasiaContext * const c = avctx->priv_data;
Michael Niedermayer's avatar
Michael Niedermayer committed
71
    const unsigned char *encoded = buf;
72
    AVFrame *frame = c->frame;
73
    int zret; // Zlib return code
74
    int ret, len = buf_size;
75

76
    if ((ret = ff_reget_buffer(avctx, frame)) < 0)
77
        return ret;
78

79
    zret = inflateReset(&c->zstream);
80 81
    if (zret != Z_OK) {
        av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", zret);
82
        return AVERROR_UNKNOWN;
83
    }
84
    c->zstream.next_in = (uint8_t*)encoded;
85 86 87
    c->zstream.avail_in = len;
    c->zstream.next_out = c->decomp_buf;
    c->zstream.avail_out = c->decomp_size;
88
    zret = inflate(&c->zstream, Z_FINISH);
89 90 91
    // Z_DATA_ERROR means empty picture
    if ((zret != Z_OK) && (zret != Z_STREAM_END) && (zret != Z_DATA_ERROR)) {
        av_log(avctx, AV_LOG_ERROR, "Inflate error: %d\n", zret);
92
        return AVERROR_UNKNOWN;
93
    }
94 95


96 97 98
    if (zret != Z_DATA_ERROR) {
        bytestream2_init(&c->gb, c->decomp_buf,
                         c->decomp_size - c->zstream.avail_out);
99
        ff_msrle_decode(avctx, (AVPicture*)frame, c->bpp, &c->gb);
100
    }
101

Mike Melanson's avatar
Mike Melanson committed
102
    /* make the palette available on the way out */
103
    if (c->avctx->pix_fmt == AV_PIX_FMT_PAL8) {
104 105 106
        const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL);

        if (pal) {
107
            frame->palette_has_changed = 1;
108
            memcpy(c->pal, pal, AVPALETTE_SIZE);
Mike Melanson's avatar
Mike Melanson committed
109
        }
110
        memcpy(frame->data[1], c->pal, AVPALETTE_SIZE);
Mike Melanson's avatar
Mike Melanson committed
111 112
    }

113 114
    if ((ret = av_frame_ref(data, frame)) < 0)
        return ret;
115
    *got_frame      = 1;
116 117 118 119 120

    /* always report that the buffer was completely consumed */
    return buf_size;
}

121
static av_cold int decode_init(AVCodecContext *avctx)
122
{
123
    CamtasiaContext * const c = avctx->priv_data;
124 125 126 127 128 129 130
    int zret; // Zlib return code

    c->avctx = avctx;

    c->height = avctx->height;

    // Needed if zlib unused or init aborted before inflateInit
131
    memset(&c->zstream, 0, sizeof(z_stream));
132
    switch(avctx->bits_per_coded_sample){
133 134
    case  8: avctx->pix_fmt = AV_PIX_FMT_PAL8; break;
    case 16: avctx->pix_fmt = AV_PIX_FMT_RGB555; break;
Roberto Togni's avatar
Roberto Togni committed
135
    case 24:
136
             avctx->pix_fmt = AV_PIX_FMT_BGR24;
137
             break;
138
    case 32: avctx->pix_fmt = AV_PIX_FMT_RGB32; break;
139
    default: av_log(avctx, AV_LOG_ERROR, "Camtasia error: unknown depth %i bpp\n", avctx->bits_per_coded_sample);
140
             return AVERROR_PATCHWELCOME;
141
    }
142
    c->bpp = avctx->bits_per_coded_sample;
143
    // buffer size for RLE 'best' case when 2-byte code precedes each pixel and there may be padding after it too
144
    c->decomp_size = (((avctx->width * c->bpp + 7) >> 3) + 3 * avctx->width + 2) * avctx->height + 2;
145 146 147 148 149

    /* Allocate decompression buffer */
    if (c->decomp_size) {
        if ((c->decomp_buf = av_malloc(c->decomp_size)) == NULL) {
            av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
150
            return AVERROR(ENOMEM);
151 152
        }
    }
153

154 155 156
    c->zstream.zalloc = Z_NULL;
    c->zstream.zfree = Z_NULL;
    c->zstream.opaque = Z_NULL;
157
    zret = inflateInit(&c->zstream);
158 159
    if (zret != Z_OK) {
        av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
160
        return AVERROR_UNKNOWN;
161 162
    }

163 164
    c->frame = av_frame_alloc();

165 166 167
    return 0;
}

168
static av_cold int decode_end(AVCodecContext *avctx)
169
{
170
    CamtasiaContext * const c = avctx->priv_data;
171

Michael Niedermayer's avatar
Michael Niedermayer committed
172
    av_freep(&c->decomp_buf);
173
    av_frame_free(&c->frame);
Michael Niedermayer's avatar
Michael Niedermayer committed
174

175
    inflateEnd(&c->zstream);
176 177 178 179

    return 0;
}

180
AVCodec ff_tscc_decoder = {
181
    .name           = "camtasia",
182
    .long_name      = NULL_IF_CONFIG_SMALL("TechSmith Screen Capture Codec"),
183
    .type           = AVMEDIA_TYPE_VIDEO,
184
    .id             = AV_CODEC_ID_TSCC,
185 186 187 188 189
    .priv_data_size = sizeof(CamtasiaContext),
    .init           = decode_init,
    .close          = decode_end,
    .decode         = decode_frame,
    .capabilities   = CODEC_CAP_DR1,
190
};