diff --git a/libavcodec/Makefile b/libavcodec/Makefile index 9a243ee242..29ec7e0b28 100644 --- a/libavcodec/Makefile +++ b/libavcodec/Makefile @@ -67,6 +67,7 @@ OBJS-$(CONFIG_DXA_DECODER) += dxa.o OBJS-$(CONFIG_EIGHTBPS_DECODER) += 8bps.o OBJS-$(CONFIG_EIGHTSVX_EXP_DECODER) += 8svx.o OBJS-$(CONFIG_EIGHTSVX_FIB_DECODER) += 8svx.o +OBJS-$(CONFIG_ESCAPE124_DECODER) += escape124.o OBJS-$(CONFIG_FFV1_DECODER) += ffv1.o rangecoder.o golomb.o OBJS-$(CONFIG_FFV1_ENCODER) += ffv1.o rangecoder.o OBJS-$(CONFIG_FFVHUFF_DECODER) += huffyuv.o diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c index c6942df0b3..ec806b18ad 100644 --- a/libavcodec/allcodecs.c +++ b/libavcodec/allcodecs.c @@ -80,6 +80,7 @@ void avcodec_register_all(void) REGISTER_DECODER (EIGHTBPS, eightbps); REGISTER_DECODER (EIGHTSVX_EXP, eightsvx_exp); REGISTER_DECODER (EIGHTSVX_FIB, eightsvx_fib); + REGISTER_DECODER (ESCAPE124, escape124); REGISTER_ENCDEC (FFV1, ffv1); REGISTER_ENCDEC (FFVHUFF, ffvhuff); REGISTER_ENCDEC (FLASHSV, flashsv); diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h index ab9c176926..f440f02b97 100644 --- a/libavcodec/avcodec.h +++ b/libavcodec/avcodec.h @@ -181,6 +181,7 @@ enum CodecID { CODEC_ID_RL2, CODEC_ID_8SVX_EXP, CODEC_ID_8SVX_FIB, + CODEC_ID_ESCAPE124, /* various PCM "codecs" */ CODEC_ID_PCM_S16LE= 0x10000, diff --git a/libavcodec/escape124.c b/libavcodec/escape124.c new file mode 100644 index 0000000000..42732eae8c --- /dev/null +++ b/libavcodec/escape124.c @@ -0,0 +1,384 @@ +/* + * 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" + +#define ALT_BITSTREAM_READER_LE +#include "bitstream.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, int bits) { + return get_bits_count(gb) + bits <= gb->size_in_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; + + avctx->pix_fmt = 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]); + + if (s->frame.data[0]) + avctx->release_buffer(avctx, &s->frame); + + return 0; +} + +static CodeBook* unpack_codebook(GetBitContext* gb, unsigned depth, + unsigned size) +{ + unsigned i, j; + CodeBook* cb; + + if (!can_safely_read(gb, size * 34)) + return NULL; + + if (size >= (INT_MAX - sizeof(CodeBook)) / sizeof(MacroBlock)) + return NULL; + cb = av_malloc(size * sizeof(MacroBlock) + sizeof(CodeBook)); + if (!cb) + return NULL; + + 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}; + +/** + * Decode a single frame + * @param avctx decoder context + * @param data decoded frame + * @param data_size size of the decoded frame + * @param buf input buffer + * @param buf_size input buffer size + * @return 0 success, -1 on error + */ +static int escape124_decode_frame(AVCodecContext *avctx, + void *data, int *data_size, + const uint8_t *buf, int buf_size) +{ + Escape124Context *s = avctx->priv_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; + + AVFrame new_frame = { { 0 } }; + + 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)) { + av_log(NULL, AV_LOG_DEBUG, "Skipping frame\n"); + + *data_size = sizeof(AVFrame); + *(AVFrame*)data = s->frame; + + 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]); + s->codebooks[i] = unpack_codebook(&gb, cb_depth, cb_size); + if (!s->codebooks[i]) + return -1; + } + } + + new_frame.reference = 3; + if (avctx->get_buffer(avctx, &new_frame)) { + av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); + return -1; + } + + new_frame_data = (uint16_t*)new_frame.data[0]; + new_stride = new_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); + + if (s->frame.data[0]) + avctx->release_buffer(avctx, &s->frame); + + *(AVFrame*)data = s->frame = new_frame; + *data_size = sizeof(AVFrame); + + return frame_size; +} + + +AVCodec escape124_decoder = { + "escape124", + CODEC_TYPE_VIDEO, + CODEC_ID_ESCAPE124, + sizeof(Escape124Context), + escape124_decode_init, + NULL, + escape124_decode_close, + escape124_decode_frame, + CODEC_CAP_DR1, +}; +