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Diffstat (limited to 'ffmpeg1/libavcodec/escape124.c')
-rw-r--r--ffmpeg1/libavcodec/escape124.c379
1 files changed, 0 insertions, 379 deletions
diff --git a/ffmpeg1/libavcodec/escape124.c b/ffmpeg1/libavcodec/escape124.c
deleted file mode 100644
index 3c83e58..0000000
--- a/ffmpeg1/libavcodec/escape124.c
+++ /dev/null
@@ -1,379 +0,0 @@
-/*
- * Escape 124 Video Decoder
- * Copyright (C) 2008 Eli Friedman (eli.friedman@gmail.com)
- *
- * 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
- */
-
-#include "avcodec.h"
-#include "internal.h"
-
-#define BITSTREAM_READER_LE
-#include "get_bits.h"
-
-typedef union MacroBlock {
- uint16_t pixels[4];
- uint32_t pixels32[2];
-} MacroBlock;
-
-typedef union SuperBlock {
- uint16_t pixels[64];
- uint32_t pixels32[32];
-} SuperBlock;
-
-typedef struct CodeBook {
- unsigned depth;
- unsigned size;
- MacroBlock* blocks;
-} CodeBook;
-
-typedef struct Escape124Context {
- AVFrame frame;
-
- unsigned num_superblocks;
-
- CodeBook codebooks[3];
-} Escape124Context;
-
-static int can_safely_read(GetBitContext* gb, uint64_t bits) {
- return get_bits_left(gb) >= bits;
-}
-
-/**
- * Initialize the decoder
- * @param avctx decoder context
- * @return 0 success, negative on error
- */
-static av_cold int escape124_decode_init(AVCodecContext *avctx)
-{
- Escape124Context *s = avctx->priv_data;
-
- avcodec_get_frame_defaults(&s->frame);
- avctx->pix_fmt = AV_PIX_FMT_RGB555;
-
- s->num_superblocks = ((unsigned)avctx->width / 8) *
- ((unsigned)avctx->height / 8);
-
- return 0;
-}
-
-static av_cold int escape124_decode_close(AVCodecContext *avctx)
-{
- unsigned i;
- Escape124Context *s = avctx->priv_data;
-
- for (i = 0; i < 3; i++)
- av_free(s->codebooks[i].blocks);
-
- av_frame_unref(&s->frame);
-
- return 0;
-}
-
-static CodeBook unpack_codebook(GetBitContext* gb, unsigned depth,
- unsigned size)
-{
- unsigned i, j;
- CodeBook cb = { 0 };
-
- if (!can_safely_read(gb, (uint64_t)size * 34))
- return cb;
-
- if (size >= INT_MAX / sizeof(MacroBlock))
- return cb;
- cb.blocks = av_malloc(size ? size * sizeof(MacroBlock) : 1);
- if (!cb.blocks)
- return cb;
-
- cb.depth = depth;
- cb.size = size;
- for (i = 0; i < size; i++) {
- unsigned mask_bits = get_bits(gb, 4);
- unsigned color0 = get_bits(gb, 15);
- unsigned color1 = get_bits(gb, 15);
-
- for (j = 0; j < 4; j++) {
- if (mask_bits & (1 << j))
- cb.blocks[i].pixels[j] = color1;
- else
- cb.blocks[i].pixels[j] = color0;
- }
- }
- return cb;
-}
-
-static unsigned decode_skip_count(GetBitContext* gb)
-{
- unsigned value;
- // This function reads a maximum of 23 bits,
- // which is within the padding space
- if (!can_safely_read(gb, 1))
- return -1;
- value = get_bits1(gb);
- if (!value)
- return value;
-
- value += get_bits(gb, 3);
- if (value != (1 + ((1 << 3) - 1)))
- return value;
-
- value += get_bits(gb, 7);
- if (value != (1 + ((1 << 3) - 1)) + ((1 << 7) - 1))
- return value;
-
- return value + get_bits(gb, 12);
-}
-
-static MacroBlock decode_macroblock(Escape124Context* s, GetBitContext* gb,
- int* codebook_index, int superblock_index)
-{
- // This function reads a maximum of 22 bits; the callers
- // guard this function appropriately
- unsigned block_index, depth;
-
- if (get_bits1(gb)) {
- static const char transitions[3][2] = { {2, 1}, {0, 2}, {1, 0} };
- *codebook_index = transitions[*codebook_index][get_bits1(gb)];
- }
-
- depth = s->codebooks[*codebook_index].depth;
-
- // depth = 0 means that this shouldn't read any bits;
- // in theory, this is the same as get_bits(gb, 0), but
- // that doesn't actually work.
- block_index = depth ? get_bits(gb, depth) : 0;
-
- if (*codebook_index == 1) {
- block_index += superblock_index << s->codebooks[1].depth;
- }
-
- // This condition can occur with invalid bitstreams and
- // *codebook_index == 2
- if (block_index >= s->codebooks[*codebook_index].size)
- return (MacroBlock) { { 0 } };
-
- return s->codebooks[*codebook_index].blocks[block_index];
-}
-
-static void insert_mb_into_sb(SuperBlock* sb, MacroBlock mb, unsigned index) {
- // Formula: ((index / 4) * 16 + (index % 4) * 2) / 2
- uint32_t *dst = sb->pixels32 + index + (index & -4);
-
- // This technically violates C99 aliasing rules, but it should be safe.
- dst[0] = mb.pixels32[0];
- dst[4] = mb.pixels32[1];
-}
-
-static void copy_superblock(uint16_t* dest, unsigned dest_stride,
- uint16_t* src, unsigned src_stride)
-{
- unsigned y;
- if (src)
- for (y = 0; y < 8; y++)
- memcpy(dest + y * dest_stride, src + y * src_stride,
- sizeof(uint16_t) * 8);
- else
- for (y = 0; y < 8; y++)
- memset(dest + y * dest_stride, 0, sizeof(uint16_t) * 8);
-}
-
-static const uint16_t mask_matrix[] = {0x1, 0x2, 0x10, 0x20,
- 0x4, 0x8, 0x40, 0x80,
- 0x100, 0x200, 0x1000, 0x2000,
- 0x400, 0x800, 0x4000, 0x8000};
-
-static int escape124_decode_frame(AVCodecContext *avctx,
- void *data, int *got_frame,
- AVPacket *avpkt)
-{
- const uint8_t *buf = avpkt->data;
- int buf_size = avpkt->size;
- Escape124Context *s = avctx->priv_data;
- AVFrame *frame = data;
-
- GetBitContext gb;
- unsigned frame_flags, frame_size;
- unsigned i;
-
- unsigned superblock_index, cb_index = 1,
- superblock_col_index = 0,
- superblocks_per_row = avctx->width / 8, skip = -1;
-
- uint16_t* old_frame_data, *new_frame_data;
- unsigned old_stride, new_stride;
-
- int ret;
-
- init_get_bits(&gb, buf, buf_size * 8);
-
- // This call also guards the potential depth reads for the
- // codebook unpacking.
- if (!can_safely_read(&gb, 64))
- return -1;
-
- frame_flags = get_bits_long(&gb, 32);
- frame_size = get_bits_long(&gb, 32);
-
- // Leave last frame unchanged
- // FIXME: Is this necessary? I haven't seen it in any real samples
- if (!(frame_flags & 0x114) || !(frame_flags & 0x7800000)) {
- if (!s->frame.data[0])
- return AVERROR_INVALIDDATA;
-
- av_log(NULL, AV_LOG_DEBUG, "Skipping frame\n");
-
- *got_frame = 1;
- if ((ret = av_frame_ref(frame, &s->frame)) < 0)
- return ret;
-
- return frame_size;
- }
-
- for (i = 0; i < 3; i++) {
- if (frame_flags & (1 << (17 + i))) {
- unsigned cb_depth, cb_size;
- if (i == 2) {
- // This codebook can be cut off at places other than
- // powers of 2, leaving some of the entries undefined.
- cb_size = get_bits_long(&gb, 20);
- cb_depth = av_log2(cb_size - 1) + 1;
- } else {
- cb_depth = get_bits(&gb, 4);
- if (i == 0) {
- // This is the most basic codebook: pow(2,depth) entries
- // for a depth-length key
- cb_size = 1 << cb_depth;
- } else {
- // This codebook varies per superblock
- // FIXME: I don't think this handles integer overflow
- // properly
- cb_size = s->num_superblocks << cb_depth;
- }
- }
- av_free(s->codebooks[i].blocks);
- s->codebooks[i] = unpack_codebook(&gb, cb_depth, cb_size);
- if (!s->codebooks[i].blocks)
- return -1;
- }
- }
-
- if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
- return ret;
-
- new_frame_data = (uint16_t*)frame->data[0];
- new_stride = frame->linesize[0] / 2;
- old_frame_data = (uint16_t*)s->frame.data[0];
- old_stride = s->frame.linesize[0] / 2;
-
- for (superblock_index = 0; superblock_index < s->num_superblocks;
- superblock_index++) {
- MacroBlock mb;
- SuperBlock sb;
- unsigned multi_mask = 0;
-
- if (skip == -1) {
- // Note that this call will make us skip the rest of the blocks
- // if the frame prematurely ends
- skip = decode_skip_count(&gb);
- }
-
- if (skip) {
- copy_superblock(new_frame_data, new_stride,
- old_frame_data, old_stride);
- } else {
- copy_superblock(sb.pixels, 8,
- old_frame_data, old_stride);
-
- while (can_safely_read(&gb, 1) && !get_bits1(&gb)) {
- unsigned mask;
- mb = decode_macroblock(s, &gb, &cb_index, superblock_index);
- mask = get_bits(&gb, 16);
- multi_mask |= mask;
- for (i = 0; i < 16; i++) {
- if (mask & mask_matrix[i]) {
- insert_mb_into_sb(&sb, mb, i);
- }
- }
- }
-
- if (can_safely_read(&gb, 1) && !get_bits1(&gb)) {
- unsigned inv_mask = get_bits(&gb, 4);
- for (i = 0; i < 4; i++) {
- if (inv_mask & (1 << i)) {
- multi_mask ^= 0xF << i*4;
- } else {
- multi_mask ^= get_bits(&gb, 4) << i*4;
- }
- }
-
- for (i = 0; i < 16; i++) {
- if (multi_mask & mask_matrix[i]) {
- if (!can_safely_read(&gb, 1))
- break;
- mb = decode_macroblock(s, &gb, &cb_index,
- superblock_index);
- insert_mb_into_sb(&sb, mb, i);
- }
- }
- } else if (frame_flags & (1 << 16)) {
- while (can_safely_read(&gb, 1) && !get_bits1(&gb)) {
- mb = decode_macroblock(s, &gb, &cb_index, superblock_index);
- insert_mb_into_sb(&sb, mb, get_bits(&gb, 4));
- }
- }
-
- copy_superblock(new_frame_data, new_stride, sb.pixels, 8);
- }
-
- superblock_col_index++;
- new_frame_data += 8;
- if (old_frame_data)
- old_frame_data += 8;
- if (superblock_col_index == superblocks_per_row) {
- new_frame_data += new_stride * 8 - superblocks_per_row * 8;
- if (old_frame_data)
- old_frame_data += old_stride * 8 - superblocks_per_row * 8;
- superblock_col_index = 0;
- }
- skip--;
- }
-
- av_log(NULL, AV_LOG_DEBUG,
- "Escape sizes: %i, %i, %i\n",
- frame_size, buf_size, get_bits_count(&gb) / 8);
-
- av_frame_unref(&s->frame);
- if ((ret = av_frame_ref(&s->frame, frame)) < 0)
- return ret;
-
- *got_frame = 1;
-
- return frame_size;
-}
-
-
-AVCodec ff_escape124_decoder = {
- .name = "escape124",
- .type = AVMEDIA_TYPE_VIDEO,
- .id = AV_CODEC_ID_ESCAPE124,
- .priv_data_size = sizeof(Escape124Context),
- .init = escape124_decode_init,
- .close = escape124_decode_close,
- .decode = escape124_decode_frame,
- .capabilities = CODEC_CAP_DR1,
- .long_name = NULL_IF_CONFIG_SMALL("Escape 124"),
-};
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