/* * MidiVid Archive codec * * Copyright (c) 2019 Paul B Mahol * * 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 <stdio.h> #include <stdlib.h> #include <string.h> #define CACHED_BITSTREAM_READER !ARCH_X86_32 #include "libavutil/intreadwrite.h" #include "avcodec.h" #include "bytestream.h" #include "get_bits.h" #include "internal.h" #include "lossless_videodsp.h" #include <zlib.h> typedef struct MVHAContext { GetBitContext gb; int nb_symbols; uint8_t symb[256]; uint32_t prob[256]; VLC vlc; z_stream zstream; LLVidDSPContext llviddsp; } MVHAContext; typedef struct Node { int16_t sym; int16_t n0; int16_t l, r; uint32_t count; } Node; static void get_tree_codes(uint32_t *bits, int16_t *lens, uint8_t *xlat, Node *nodes, int node, uint32_t pfx, int pl, int *pos) { int s; s = nodes[node].sym; if (s != -1) { bits[*pos] = (~pfx) & ((1ULL << FFMAX(pl, 1)) - 1); lens[*pos] = FFMAX(pl, 1); xlat[*pos] = s + (pl == 0); (*pos)++; } else { pfx <<= 1; pl++; get_tree_codes(bits, lens, xlat, nodes, nodes[node].l, pfx, pl, pos); pfx |= 1; get_tree_codes(bits, lens, xlat, nodes, nodes[node].r, pfx, pl, pos); } } static int build_vlc(AVCodecContext *avctx, VLC *vlc) { MVHAContext *s = avctx->priv_data; Node nodes[512]; uint32_t bits[256]; int16_t lens[256]; uint8_t xlat[256]; int cur_node, i, j, pos = 0; ff_free_vlc(vlc); for (i = 0; i < s->nb_symbols; i++) { nodes[i].count = s->prob[i]; nodes[i].sym = s->symb[i]; nodes[i].n0 = -2; nodes[i].l = i; nodes[i].r = i; } cur_node = s->nb_symbols; j = 0; do { for (i = 0; ; i++) { int new_node = j; int first_node = cur_node; int second_node = cur_node; unsigned nd, st; nodes[cur_node].count = -1; do { int val = nodes[new_node].count; if (val && (val < nodes[first_node].count)) { if (val >= nodes[second_node].count) { first_node = new_node; } else { first_node = second_node; second_node = new_node; } } new_node += 1; } while (new_node != cur_node); if (first_node == cur_node) break; nd = nodes[second_node].count; st = nodes[first_node].count; nodes[second_node].count = 0; nodes[first_node].count = 0; if (nd >= UINT32_MAX - st) { av_log(avctx, AV_LOG_ERROR, "count overflow\n"); return AVERROR_INVALIDDATA; } nodes[cur_node].count = nd + st; nodes[cur_node].sym = -1; nodes[cur_node].n0 = cur_node; nodes[cur_node].l = first_node; nodes[cur_node].r = second_node; cur_node++; } j++; } while (cur_node - s->nb_symbols == j); get_tree_codes(bits, lens, xlat, nodes, cur_node - 1, 0, 0, &pos); return ff_init_vlc_sparse(vlc, 12, pos, lens, 2, 2, bits, 4, 4, xlat, 1, 1, 0); } static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt) { MVHAContext *s = avctx->priv_data; AVFrame *frame = data; uint32_t type, size; int ret; if (avpkt->size <= 8) return AVERROR_INVALIDDATA; type = AV_RB32(avpkt->data); size = AV_RL32(avpkt->data + 4); if (size < 1 || size >= avpkt->size) return AVERROR_INVALIDDATA; if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) return ret; if (type == MKTAG('L','Z','Y','V')) { ret = inflateReset(&s->zstream); if (ret != Z_OK) { av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", ret); return AVERROR_EXTERNAL; } s->zstream.next_in = avpkt->data + 8; s->zstream.avail_in = avpkt->size - 8; for (int p = 0; p < 3; p++) { for (int y = 0; y < avctx->height; y++) { s->zstream.next_out = frame->data[p] + (avctx->height - y - 1) * frame->linesize[p]; s->zstream.avail_out = avctx->width >> (p > 0); ret = inflate(&s->zstream, Z_SYNC_FLUSH); if (ret != Z_OK && ret != Z_STREAM_END) { av_log(avctx, AV_LOG_ERROR, "Inflate error: %d\n", ret); return AVERROR_EXTERNAL; } } } } else if (type == MKTAG('H','U','F','Y')) { GetBitContext *gb = &s->gb; int first_symbol, symbol; ret = init_get_bits8(gb, avpkt->data + 8, avpkt->size - 8); if (ret < 0) return ret; skip_bits(gb, 24); first_symbol = get_bits(gb, 8); s->nb_symbols = get_bits(gb, 8) + 1; symbol = first_symbol; for (int i = 0; i < s->nb_symbols; symbol++) { int prob; if (get_bits_left(gb) < 4) return AVERROR_INVALIDDATA; if (get_bits1(gb)) { prob = get_bits(gb, 12); } else { prob = get_bits(gb, 3); } if (prob) { s->symb[i] = symbol; s->prob[i] = prob; i++; } } ret = build_vlc(avctx, &s->vlc); if (ret < 0) return ret; for (int p = 0; p < 3; p++) { int width = avctx->width >> (p > 0); ptrdiff_t stride = frame->linesize[p]; uint8_t *dst; dst = frame->data[p] + (avctx->height - 1) * frame->linesize[p]; for (int y = 0; y < avctx->height; y++) { if (get_bits_left(gb) < width) return AVERROR_INVALIDDATA; for (int x = 0; x < width; x++) { int v = get_vlc2(gb, s->vlc.table, s->vlc.bits, 3); if (v < 0) return AVERROR_INVALIDDATA; dst[x] = v; } dst -= stride; } } } else { return AVERROR_INVALIDDATA; } for (int p = 0; p < 3; p++) { int left, lefttop; int width = avctx->width >> (p > 0); ptrdiff_t stride = frame->linesize[p]; uint8_t *dst; dst = frame->data[p] + (avctx->height - 1) * frame->linesize[p]; s->llviddsp.add_left_pred(dst, dst, width, 0); if (avctx->height > 1) { dst -= stride; lefttop = left = dst[0]; for (int y = 1; y < avctx->height; y++) { s->llviddsp.add_median_pred(dst, dst + stride, dst, width, &left, &lefttop); lefttop = left = dst[0]; dst -= stride; } } } frame->pict_type = AV_PICTURE_TYPE_I; frame->key_frame = 1; *got_frame = 1; return avpkt->size; } static av_cold int decode_init(AVCodecContext *avctx) { MVHAContext *s = avctx->priv_data; int zret; avctx->pix_fmt = AV_PIX_FMT_YUV422P; s->zstream.zalloc = Z_NULL; s->zstream.zfree = Z_NULL; s->zstream.opaque = Z_NULL; zret = inflateInit(&s->zstream); if (zret != Z_OK) { av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret); return AVERROR_EXTERNAL; } ff_llviddsp_init(&s->llviddsp); return 0; } static av_cold int decode_close(AVCodecContext *avctx) { MVHAContext *s = avctx->priv_data; inflateEnd(&s->zstream); ff_free_vlc(&s->vlc); return 0; } AVCodec ff_mvha_decoder = { .name = "mvha", .long_name = NULL_IF_CONFIG_SMALL("MidiVid Archive Codec"), .type = AVMEDIA_TYPE_VIDEO, .id = AV_CODEC_ID_MVHA, .priv_data_size = sizeof(MVHAContext), .init = decode_init, .close = decode_close, .decode = decode_frame, .capabilities = AV_CODEC_CAP_DR1, .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP, };