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This is possible, because every given FFCodec has to implement exactly one of these. Doing so decreases sizeof(FFCodec) and therefore decreases the size of the binary. Notice that in case of position-independent code the decrease is in .data.rel.ro, so that this translates to decreased memory consumption. Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
276 lines
7.9 KiB
C
276 lines
7.9 KiB
C
/*
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* Tiertex Limited SEQ Video Decoder
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* Copyright (c) 2006 Gregory Montoir (cyx@users.sourceforge.net)
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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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* Tiertex Limited SEQ video decoder
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*/
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#define BITSTREAM_READER_LE
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#include "avcodec.h"
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#include "codec_internal.h"
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#include "get_bits.h"
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#include "internal.h"
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typedef struct SeqVideoContext {
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AVCodecContext *avctx;
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AVFrame *frame;
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} SeqVideoContext;
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static const unsigned char *seq_unpack_rle_block(const unsigned char *src,
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const unsigned char *src_end,
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unsigned char *dst, int dst_size)
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{
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int i, len, sz;
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GetBitContext gb;
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int code_table[64];
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/* get the rle codes */
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init_get_bits(&gb, src, (src_end - src) * 8);
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for (i = 0, sz = 0; i < 64 && sz < dst_size; i++) {
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if (get_bits_left(&gb) < 4)
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return NULL;
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code_table[i] = get_sbits(&gb, 4);
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sz += FFABS(code_table[i]);
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}
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src += (get_bits_count(&gb) + 7) / 8;
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/* do the rle unpacking */
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for (i = 0; i < 64 && dst_size > 0; i++) {
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len = code_table[i];
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if (len < 0) {
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len = -len;
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if (src_end - src < 1)
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return NULL;
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memset(dst, *src++, FFMIN(len, dst_size));
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} else {
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if (src_end - src < len)
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return NULL;
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memcpy(dst, src, FFMIN(len, dst_size));
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src += len;
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}
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dst += len;
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dst_size -= len;
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}
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return src;
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}
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static const unsigned char *seq_decode_op1(SeqVideoContext *seq,
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const unsigned char *src,
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const unsigned char *src_end,
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unsigned char *dst)
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{
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const unsigned char *color_table;
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int b, i, len, bits;
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GetBitContext gb;
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unsigned char block[8 * 8];
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if (src_end - src < 1)
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return NULL;
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len = *src++;
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if (len & 0x80) {
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switch (len & 3) {
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case 1:
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src = seq_unpack_rle_block(src, src_end, block, sizeof(block));
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for (b = 0; b < 8; b++) {
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memcpy(dst, &block[b * 8], 8);
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dst += seq->frame->linesize[0];
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}
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break;
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case 2:
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src = seq_unpack_rle_block(src, src_end, block, sizeof(block));
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for (i = 0; i < 8; i++) {
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for (b = 0; b < 8; b++)
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dst[b * seq->frame->linesize[0]] = block[i * 8 + b];
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++dst;
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}
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break;
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}
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} else {
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if (len <= 0)
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return NULL;
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bits = ff_log2_tab[len - 1] + 1;
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if (src_end - src < len + 8 * bits)
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return NULL;
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color_table = src;
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src += len;
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init_get_bits(&gb, src, bits * 8 * 8); src += bits * 8;
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for (b = 0; b < 8; b++) {
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for (i = 0; i < 8; i++)
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dst[i] = color_table[get_bits(&gb, bits)];
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dst += seq->frame->linesize[0];
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}
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}
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return src;
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}
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static const unsigned char *seq_decode_op2(SeqVideoContext *seq,
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const unsigned char *src,
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const unsigned char *src_end,
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unsigned char *dst)
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{
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int i;
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if (src_end - src < 8 * 8)
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return NULL;
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for (i = 0; i < 8; i++) {
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memcpy(dst, src, 8);
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src += 8;
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dst += seq->frame->linesize[0];
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}
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return src;
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}
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static const unsigned char *seq_decode_op3(SeqVideoContext *seq,
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const unsigned char *src,
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const unsigned char *src_end,
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unsigned char *dst)
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{
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int pos, offset;
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do {
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if (src_end - src < 2)
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return NULL;
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pos = *src++;
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offset = ((pos >> 3) & 7) * seq->frame->linesize[0] + (pos & 7);
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dst[offset] = *src++;
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} while (!(pos & 0x80));
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return src;
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}
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static int seqvideo_decode(SeqVideoContext *seq, const unsigned char *data, int data_size)
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{
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const unsigned char *data_end = data + data_size;
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GetBitContext gb;
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int flags, i, j, x, y, op;
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unsigned char c[3];
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unsigned char *dst;
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uint32_t *palette;
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flags = *data++;
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if (flags & 1) {
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palette = (uint32_t *)seq->frame->data[1];
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if (data_end - data < 256 * 3)
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return AVERROR_INVALIDDATA;
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for (i = 0; i < 256; i++) {
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for (j = 0; j < 3; j++, data++)
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c[j] = (*data << 2) | (*data >> 4);
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palette[i] = 0xFFU << 24 | AV_RB24(c);
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}
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seq->frame->palette_has_changed = 1;
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}
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if (flags & 2) {
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if (data_end - data < 128)
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return AVERROR_INVALIDDATA;
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init_get_bits(&gb, data, 128 * 8); data += 128;
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for (y = 0; y < 128; y += 8)
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for (x = 0; x < 256; x += 8) {
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dst = &seq->frame->data[0][y * seq->frame->linesize[0] + x];
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op = get_bits(&gb, 2);
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switch (op) {
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case 1:
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data = seq_decode_op1(seq, data, data_end, dst);
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break;
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case 2:
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data = seq_decode_op2(seq, data, data_end, dst);
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break;
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case 3:
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data = seq_decode_op3(seq, data, data_end, dst);
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break;
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}
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if (!data)
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return AVERROR_INVALIDDATA;
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}
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}
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return 0;
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}
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static av_cold int seqvideo_decode_init(AVCodecContext *avctx)
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{
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SeqVideoContext *seq = avctx->priv_data;
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int ret;
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seq->avctx = avctx;
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avctx->pix_fmt = AV_PIX_FMT_PAL8;
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ret = ff_set_dimensions(avctx, 256, 128);
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if (ret < 0)
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return ret;
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seq->frame = av_frame_alloc();
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if (!seq->frame)
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return AVERROR(ENOMEM);
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return 0;
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}
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static int seqvideo_decode_frame(AVCodecContext *avctx, AVFrame *rframe,
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int *got_frame, 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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int ret;
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SeqVideoContext *seq = avctx->priv_data;
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if ((ret = ff_reget_buffer(avctx, seq->frame, 0)) < 0)
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return ret;
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if (seqvideo_decode(seq, buf, buf_size))
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return AVERROR_INVALIDDATA;
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if ((ret = av_frame_ref(rframe, seq->frame)) < 0)
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return ret;
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*got_frame = 1;
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return buf_size;
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}
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static av_cold int seqvideo_decode_end(AVCodecContext *avctx)
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{
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SeqVideoContext *seq = avctx->priv_data;
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av_frame_free(&seq->frame);
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return 0;
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}
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const FFCodec ff_tiertexseqvideo_decoder = {
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.p.name = "tiertexseqvideo",
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.p.long_name = NULL_IF_CONFIG_SMALL("Tiertex Limited SEQ video"),
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.p.type = AVMEDIA_TYPE_VIDEO,
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.p.id = AV_CODEC_ID_TIERTEXSEQVIDEO,
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.priv_data_size = sizeof(SeqVideoContext),
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.init = seqvideo_decode_init,
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.close = seqvideo_decode_end,
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FF_CODEC_DECODE_CB(seqvideo_decode_frame),
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.p.capabilities = AV_CODEC_CAP_DR1,
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.caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
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};
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