| /* |
| * Tiertex Limited SEQ Video Decoder |
| * Copyright (c) 2006 Gregory Montoir (cyx@users.sourceforge.net) |
| * |
| * This file is part of FFmpeg. |
| * |
| * FFmpeg is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Lesser General Public |
| * License as published by the Free Software Foundation; either |
| * version 2.1 of the License, or (at your option) any later version. |
| * |
| * FFmpeg is distributed in the hope that it will be useful, |
| * 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 |
| * License along with FFmpeg; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| */ |
| |
| /** |
| * @file |
| * Tiertex Limited SEQ video decoder |
| */ |
| |
| #include "avcodec.h" |
| #define BITSTREAM_READER_LE |
| #include "get_bits.h" |
| #include "internal.h" |
| |
| |
| typedef struct SeqVideoContext { |
| AVCodecContext *avctx; |
| AVFrame *frame; |
| } SeqVideoContext; |
| |
| |
| static const unsigned char *seq_unpack_rle_block(const unsigned char *src, |
| const unsigned char *src_end, |
| unsigned char *dst, int dst_size) |
| { |
| int i, len, sz; |
| GetBitContext gb; |
| int code_table[64]; |
| |
| /* get the rle codes */ |
| init_get_bits(&gb, src, (src_end - src) * 8); |
| for (i = 0, sz = 0; i < 64 && sz < dst_size; i++) { |
| if (get_bits_left(&gb) < 4) |
| return NULL; |
| code_table[i] = get_sbits(&gb, 4); |
| sz += FFABS(code_table[i]); |
| } |
| src += (get_bits_count(&gb) + 7) / 8; |
| |
| /* do the rle unpacking */ |
| for (i = 0; i < 64 && dst_size > 0; i++) { |
| len = code_table[i]; |
| if (len < 0) { |
| len = -len; |
| if (src_end - src < 1) |
| return NULL; |
| memset(dst, *src++, FFMIN(len, dst_size)); |
| } else { |
| if (src_end - src < len) |
| return NULL; |
| memcpy(dst, src, FFMIN(len, dst_size)); |
| src += len; |
| } |
| dst += len; |
| dst_size -= len; |
| } |
| return src; |
| } |
| |
| static const unsigned char *seq_decode_op1(SeqVideoContext *seq, |
| const unsigned char *src, |
| const unsigned char *src_end, |
| unsigned char *dst) |
| { |
| const unsigned char *color_table; |
| int b, i, len, bits; |
| GetBitContext gb; |
| unsigned char block[8 * 8]; |
| |
| if (src_end - src < 1) |
| return NULL; |
| len = *src++; |
| if (len & 0x80) { |
| switch (len & 3) { |
| case 1: |
| src = seq_unpack_rle_block(src, src_end, block, sizeof(block)); |
| for (b = 0; b < 8; b++) { |
| memcpy(dst, &block[b * 8], 8); |
| dst += seq->frame->linesize[0]; |
| } |
| break; |
| case 2: |
| src = seq_unpack_rle_block(src, src_end, block, sizeof(block)); |
| for (i = 0; i < 8; i++) { |
| for (b = 0; b < 8; b++) |
| dst[b * seq->frame->linesize[0]] = block[i * 8 + b]; |
| ++dst; |
| } |
| break; |
| } |
| } else { |
| if (len <= 0) |
| return NULL; |
| bits = ff_log2_tab[len - 1] + 1; |
| if (src_end - src < len + 8 * bits) |
| return NULL; |
| color_table = src; |
| src += len; |
| init_get_bits(&gb, src, bits * 8 * 8); src += bits * 8; |
| for (b = 0; b < 8; b++) { |
| for (i = 0; i < 8; i++) |
| dst[i] = color_table[get_bits(&gb, bits)]; |
| dst += seq->frame->linesize[0]; |
| } |
| } |
| |
| return src; |
| } |
| |
| static const unsigned char *seq_decode_op2(SeqVideoContext *seq, |
| const unsigned char *src, |
| const unsigned char *src_end, |
| unsigned char *dst) |
| { |
| int i; |
| |
| if (src_end - src < 8 * 8) |
| return NULL; |
| |
| for (i = 0; i < 8; i++) { |
| memcpy(dst, src, 8); |
| src += 8; |
| dst += seq->frame->linesize[0]; |
| } |
| |
| return src; |
| } |
| |
| static const unsigned char *seq_decode_op3(SeqVideoContext *seq, |
| const unsigned char *src, |
| const unsigned char *src_end, |
| unsigned char *dst) |
| { |
| int pos, offset; |
| |
| do { |
| if (src_end - src < 2) |
| return NULL; |
| pos = *src++; |
| offset = ((pos >> 3) & 7) * seq->frame->linesize[0] + (pos & 7); |
| dst[offset] = *src++; |
| } while (!(pos & 0x80)); |
| |
| return src; |
| } |
| |
| static int seqvideo_decode(SeqVideoContext *seq, const unsigned char *data, int data_size) |
| { |
| const unsigned char *data_end = data + data_size; |
| GetBitContext gb; |
| int flags, i, j, x, y, op; |
| unsigned char c[3]; |
| unsigned char *dst; |
| uint32_t *palette; |
| |
| flags = *data++; |
| |
| if (flags & 1) { |
| palette = (uint32_t *)seq->frame->data[1]; |
| if (data_end - data < 256 * 3) |
| return AVERROR_INVALIDDATA; |
| for (i = 0; i < 256; i++) { |
| for (j = 0; j < 3; j++, data++) |
| c[j] = (*data << 2) | (*data >> 4); |
| palette[i] = 0xFFU << 24 | AV_RB24(c); |
| } |
| seq->frame->palette_has_changed = 1; |
| } |
| |
| if (flags & 2) { |
| if (data_end - data < 128) |
| return AVERROR_INVALIDDATA; |
| init_get_bits(&gb, data, 128 * 8); data += 128; |
| for (y = 0; y < 128; y += 8) |
| for (x = 0; x < 256; x += 8) { |
| dst = &seq->frame->data[0][y * seq->frame->linesize[0] + x]; |
| op = get_bits(&gb, 2); |
| switch (op) { |
| case 1: |
| data = seq_decode_op1(seq, data, data_end, dst); |
| break; |
| case 2: |
| data = seq_decode_op2(seq, data, data_end, dst); |
| break; |
| case 3: |
| data = seq_decode_op3(seq, data, data_end, dst); |
| break; |
| } |
| if (!data) |
| return AVERROR_INVALIDDATA; |
| } |
| } |
| return 0; |
| } |
| |
| static av_cold int seqvideo_decode_init(AVCodecContext *avctx) |
| { |
| SeqVideoContext *seq = avctx->priv_data; |
| |
| seq->avctx = avctx; |
| avctx->pix_fmt = AV_PIX_FMT_PAL8; |
| |
| seq->frame = av_frame_alloc(); |
| if (!seq->frame) |
| return AVERROR(ENOMEM); |
| |
| return 0; |
| } |
| |
| static int seqvideo_decode_frame(AVCodecContext *avctx, |
| void *data, int *got_frame, |
| AVPacket *avpkt) |
| { |
| const uint8_t *buf = avpkt->data; |
| int buf_size = avpkt->size; |
| int ret; |
| |
| SeqVideoContext *seq = avctx->priv_data; |
| |
| if ((ret = ff_reget_buffer(avctx, seq->frame)) < 0) |
| return ret; |
| |
| if (seqvideo_decode(seq, buf, buf_size)) |
| return AVERROR_INVALIDDATA; |
| |
| if ((ret = av_frame_ref(data, seq->frame)) < 0) |
| return ret; |
| *got_frame = 1; |
| |
| return buf_size; |
| } |
| |
| static av_cold int seqvideo_decode_end(AVCodecContext *avctx) |
| { |
| SeqVideoContext *seq = avctx->priv_data; |
| |
| av_frame_free(&seq->frame); |
| |
| return 0; |
| } |
| |
| AVCodec ff_tiertexseqvideo_decoder = { |
| .name = "tiertexseqvideo", |
| .long_name = NULL_IF_CONFIG_SMALL("Tiertex Limited SEQ video"), |
| .type = AVMEDIA_TYPE_VIDEO, |
| .id = AV_CODEC_ID_TIERTEXSEQVIDEO, |
| .priv_data_size = sizeof(SeqVideoContext), |
| .init = seqvideo_decode_init, |
| .close = seqvideo_decode_end, |
| .decode = seqvideo_decode_frame, |
| .capabilities = AV_CODEC_CAP_DR1, |
| }; |