GCC Code Coverage Report
Directory: ../../../ffmpeg/ Exec Total Coverage
File: src/libavcodec/tscc.c Lines: 54 72 75.0 %
Date: 2021-04-15 16:04:23 Branches: 19 35 54.3 %

Line Branch Exec Source
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/*
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 * TechSmith Camtasia decoder
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 * Copyright (c) 2004 Konstantin Shishkov
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 *
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 * This file is part of FFmpeg.
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 *
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 * FFmpeg is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * FFmpeg is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with FFmpeg; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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/**
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 * @file
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 * TechSmith Camtasia decoder
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 *
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 * Fourcc: TSCC
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 *
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 * Codec is very simple:
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 *  it codes picture (picture difference, really)
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 *  with algorithm almost identical to Windows RLE8,
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 *  only without padding and with greater pixel sizes,
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 *  then this coded picture is packed with ZLib
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 *
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 * Supports: BGR8,BGR555,BGR24 - only BGR8 and BGR555 tested
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 */
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#include <stdio.h>
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#include <stdlib.h>
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#include "avcodec.h"
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#include "decode.h"
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#include "internal.h"
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#include "msrledec.h"
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#include <zlib.h>
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typedef struct TsccContext {
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    AVCodecContext *avctx;
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    AVFrame *frame;
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    // Bits per pixel
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    int bpp;
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    // Decompressed data size
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    unsigned int decomp_size;
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    // Decompression buffer
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    unsigned char* decomp_buf;
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    GetByteContext gb;
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    int height;
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    z_stream zstream;
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    uint32_t pal[256];
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} CamtasiaContext;
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static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
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                        AVPacket *avpkt)
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{
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    const uint8_t *buf = avpkt->data;
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    int buf_size = avpkt->size;
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    CamtasiaContext * const c = avctx->priv_data;
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    AVFrame *frame = c->frame;
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    int ret;
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    int palette_has_changed = 0;
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    if (c->avctx->pix_fmt == AV_PIX_FMT_PAL8) {
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        palette_has_changed = ff_copy_palette(c->pal, avpkt, avctx);
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    }
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    ret = inflateReset(&c->zstream);
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    if (ret != Z_OK) {
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        av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", ret);
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        return AVERROR_UNKNOWN;
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    }
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    c->zstream.next_in   = buf;
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    c->zstream.avail_in  = buf_size;
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    c->zstream.next_out = c->decomp_buf;
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    c->zstream.avail_out = c->decomp_size;
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    ret = inflate(&c->zstream, Z_FINISH);
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    // Z_DATA_ERROR means empty picture
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    if (ret == Z_DATA_ERROR && !palette_has_changed) {
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        return buf_size;
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    }
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    if ((ret != Z_OK) && (ret != Z_STREAM_END) && (ret != Z_DATA_ERROR)) {
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        av_log(avctx, AV_LOG_ERROR, "Inflate error: %d\n", ret);
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1
        return AVERROR_UNKNOWN;
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    }
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    if ((ret = ff_reget_buffer(avctx, frame, 0)) < 0)
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        return ret;
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    if (ret != Z_DATA_ERROR) {
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        bytestream2_init(&c->gb, c->decomp_buf,
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                         c->decomp_size - c->zstream.avail_out);
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        ff_msrle_decode(avctx, frame, c->bpp, &c->gb);
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    }
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    /* make the palette available on the way out */
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    if (c->avctx->pix_fmt == AV_PIX_FMT_PAL8) {
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        frame->palette_has_changed = palette_has_changed;
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        memcpy(frame->data[1], c->pal, AVPALETTE_SIZE);
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    }
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    if ((ret = av_frame_ref(data, frame)) < 0)
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        return ret;
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    *got_frame      = 1;
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    /* always report that the buffer was completely consumed */
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    return buf_size;
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}
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static av_cold int decode_init(AVCodecContext *avctx)
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{
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    CamtasiaContext * const c = avctx->priv_data;
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    int zret; // Zlib return code
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    c->avctx = avctx;
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    c->height = avctx->height;
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    // Needed if zlib unused or init aborted before inflateInit
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    memset(&c->zstream, 0, sizeof(z_stream));
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    switch(avctx->bits_per_coded_sample){
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    case  8: avctx->pix_fmt = AV_PIX_FMT_PAL8; break;
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    case 16: avctx->pix_fmt = AV_PIX_FMT_RGB555; break;
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    case 24:
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             avctx->pix_fmt = AV_PIX_FMT_BGR24;
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             break;
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    case 32: avctx->pix_fmt = AV_PIX_FMT_0RGB32; break;
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    default: av_log(avctx, AV_LOG_ERROR, "Camtasia error: unknown depth %i bpp\n", avctx->bits_per_coded_sample);
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             return AVERROR_PATCHWELCOME;
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    }
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    c->bpp = avctx->bits_per_coded_sample;
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    // buffer size for RLE 'best' case when 2-byte code precedes each pixel and there may be padding after it too
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    c->decomp_size = (((avctx->width * c->bpp + 7) >> 3) + 3 * avctx->width + 2) * avctx->height + 2;
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    /* Allocate decompression buffer */
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    if (c->decomp_size) {
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        if (!(c->decomp_buf = av_malloc(c->decomp_size))) {
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            av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
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            return AVERROR(ENOMEM);
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        }
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    }
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    c->zstream.zalloc = Z_NULL;
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    c->zstream.zfree = Z_NULL;
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    c->zstream.opaque = Z_NULL;
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    zret = inflateInit(&c->zstream);
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    if (zret != Z_OK) {
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        av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
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        return AVERROR_UNKNOWN;
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    }
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    c->frame = av_frame_alloc();
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    if (!c->frame)
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        return AVERROR(ENOMEM);
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    return 0;
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}
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static av_cold int decode_end(AVCodecContext *avctx)
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{
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    CamtasiaContext * const c = avctx->priv_data;
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    av_freep(&c->decomp_buf);
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    av_frame_free(&c->frame);
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    inflateEnd(&c->zstream);
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    return 0;
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}
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AVCodec ff_tscc_decoder = {
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    .name           = "camtasia",
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    .long_name      = NULL_IF_CONFIG_SMALL("TechSmith Screen Capture Codec"),
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    .type           = AVMEDIA_TYPE_VIDEO,
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    .id             = AV_CODEC_ID_TSCC,
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    .priv_data_size = sizeof(CamtasiaContext),
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    .init           = decode_init,
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    .close          = decode_end,
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    .decode         = decode_frame,
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    .capabilities   = AV_CODEC_CAP_DR1,
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    .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP,
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};