| /* |
| * MidiVid decoder |
| * 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> |
| |
| #include "libavutil/imgutils.h" |
| #include "libavutil/internal.h" |
| #include "libavutil/intreadwrite.h" |
| #include "libavutil/mem.h" |
| |
| #define BITSTREAM_READER_LE |
| #include "avcodec.h" |
| #include "get_bits.h" |
| #include "bytestream.h" |
| #include "internal.h" |
| |
| typedef struct MidiVidContext { |
| GetByteContext gb; |
| |
| uint8_t *uncompressed; |
| unsigned int uncompressed_size; |
| uint8_t *skip; |
| |
| AVFrame *frame; |
| } MidiVidContext; |
| |
| static int decode_mvdv(MidiVidContext *s, AVCodecContext *avctx, AVFrame *frame) |
| { |
| GetByteContext *gb = &s->gb; |
| GetBitContext mask; |
| GetByteContext idx9; |
| uint16_t nb_vectors, intra_flag; |
| const uint8_t *vec; |
| const uint8_t *mask_start; |
| uint8_t *skip; |
| uint32_t mask_size; |
| int idx9bits = 0; |
| int idx9val = 0; |
| uint32_t nb_blocks; |
| |
| nb_vectors = bytestream2_get_le16(gb); |
| intra_flag = !!bytestream2_get_le16(gb); |
| if (intra_flag) { |
| nb_blocks = (avctx->width / 2) * (avctx->height / 2); |
| } else { |
| int ret, skip_linesize, padding; |
| |
| nb_blocks = bytestream2_get_le32(gb); |
| skip_linesize = avctx->width >> 1; |
| mask_start = gb->buffer_start + bytestream2_tell(gb); |
| mask_size = (FFALIGN(avctx->width, 32) >> 2) * (avctx->height >> 2) >> 3; |
| padding = (FFALIGN(avctx->width, 32) - avctx->width) >> 2; |
| |
| if (bytestream2_get_bytes_left(gb) < mask_size) |
| return AVERROR_INVALIDDATA; |
| |
| ret = init_get_bits8(&mask, mask_start, mask_size); |
| if (ret < 0) |
| return ret; |
| bytestream2_skip(gb, mask_size); |
| skip = s->skip; |
| |
| for (int y = 0; y < avctx->height >> 2; y++) { |
| for (int x = 0; x < avctx->width >> 2; x++) { |
| int flag = !get_bits1(&mask); |
| |
| skip[(y*2) *skip_linesize + x*2 ] = flag; |
| skip[(y*2) *skip_linesize + x*2+1] = flag; |
| skip[(y*2+1)*skip_linesize + x*2 ] = flag; |
| skip[(y*2+1)*skip_linesize + x*2+1] = flag; |
| } |
| skip_bits_long(&mask, padding); |
| } |
| } |
| |
| vec = gb->buffer_start + bytestream2_tell(gb); |
| if (bytestream2_get_bytes_left(gb) < nb_vectors * 12) |
| return AVERROR_INVALIDDATA; |
| bytestream2_skip(gb, nb_vectors * 12); |
| if (nb_vectors > 256) { |
| if (bytestream2_get_bytes_left(gb) < (nb_blocks + 7 * !intra_flag) / 8) |
| return AVERROR_INVALIDDATA; |
| bytestream2_init(&idx9, gb->buffer_start + bytestream2_tell(gb), (nb_blocks + 7 * !intra_flag) / 8); |
| bytestream2_skip(gb, (nb_blocks + 7 * !intra_flag) / 8); |
| } |
| |
| skip = s->skip; |
| |
| for (int y = avctx->height - 2; y >= 0; y -= 2) { |
| uint8_t *dsty = frame->data[0] + y * frame->linesize[0]; |
| uint8_t *dstu = frame->data[1] + y * frame->linesize[1]; |
| uint8_t *dstv = frame->data[2] + y * frame->linesize[2]; |
| |
| for (int x = 0; x < avctx->width; x += 2) { |
| int idx; |
| |
| if (!intra_flag && *skip++) |
| continue; |
| if (bytestream2_get_bytes_left(gb) <= 0) |
| return AVERROR_INVALIDDATA; |
| if (nb_vectors <= 256) { |
| idx = bytestream2_get_byte(gb); |
| } else { |
| if (idx9bits == 0) { |
| idx9val = bytestream2_get_byte(&idx9); |
| idx9bits = 8; |
| } |
| idx9bits--; |
| idx = bytestream2_get_byte(gb) | (((idx9val >> (7 - idx9bits)) & 1) << 8); |
| } |
| if (idx >= nb_vectors) |
| return AVERROR_INVALIDDATA; |
| |
| dsty[x +frame->linesize[0]] = vec[idx * 12 + 0]; |
| dsty[x+1+frame->linesize[0]] = vec[idx * 12 + 3]; |
| dsty[x] = vec[idx * 12 + 6]; |
| dsty[x+1] = vec[idx * 12 + 9]; |
| |
| dstu[x +frame->linesize[1]] = vec[idx * 12 + 1]; |
| dstu[x+1+frame->linesize[1]] = vec[idx * 12 + 4]; |
| dstu[x] = vec[idx * 12 + 7]; |
| dstu[x+1] = vec[idx * 12 +10]; |
| |
| dstv[x +frame->linesize[2]] = vec[idx * 12 + 2]; |
| dstv[x+1+frame->linesize[2]] = vec[idx * 12 + 5]; |
| dstv[x] = vec[idx * 12 + 8]; |
| dstv[x+1] = vec[idx * 12 +11]; |
| } |
| } |
| |
| return intra_flag; |
| } |
| |
| static ptrdiff_t lzss_uncompress(MidiVidContext *s, GetByteContext *gb, uint8_t *dst, unsigned int size) |
| { |
| uint8_t *dst_start = dst; |
| uint8_t *dst_end = dst + size; |
| |
| for (;bytestream2_get_bytes_left(gb) >= 3;) { |
| int op = bytestream2_get_le16(gb); |
| |
| for (int i = 0; i < 16; i++) { |
| if (op & 1) { |
| int s0 = bytestream2_get_byte(gb); |
| int s1 = bytestream2_get_byte(gb); |
| int offset = ((s0 & 0xF0) << 4) | s1; |
| int length = (s0 & 0xF) + 3; |
| |
| if (dst + length > dst_end || |
| dst - offset < dst_start) |
| return AVERROR_INVALIDDATA; |
| if (offset > 0) { |
| for (int j = 0; j < length; j++) { |
| dst[j] = dst[j - offset]; |
| } |
| } |
| dst += length; |
| } else { |
| if (dst >= dst_end) |
| return AVERROR_INVALIDDATA; |
| *dst++ = bytestream2_get_byte(gb); |
| } |
| op >>= 1; |
| } |
| } |
| |
| return dst - dst_start; |
| } |
| |
| static int decode_frame(AVCodecContext *avctx, void *data, |
| int *got_frame, AVPacket *avpkt) |
| { |
| MidiVidContext *s = avctx->priv_data; |
| GetByteContext *gb = &s->gb; |
| AVFrame *frame = s->frame; |
| int ret, key, uncompressed; |
| |
| if (avpkt->size <= 13) |
| return AVERROR_INVALIDDATA; |
| |
| bytestream2_init(gb, avpkt->data, avpkt->size); |
| bytestream2_skip(gb, 8); |
| uncompressed = bytestream2_get_le32(gb); |
| |
| if ((ret = ff_reget_buffer(avctx, s->frame, 0)) < 0) |
| return ret; |
| |
| if (uncompressed) { |
| ret = decode_mvdv(s, avctx, frame); |
| } else { |
| av_fast_padded_malloc(&s->uncompressed, &s->uncompressed_size, 16LL * (avpkt->size - 12)); |
| if (!s->uncompressed) |
| return AVERROR(ENOMEM); |
| |
| ret = lzss_uncompress(s, gb, s->uncompressed, s->uncompressed_size); |
| if (ret < 0) |
| return ret; |
| bytestream2_init(gb, s->uncompressed, ret); |
| ret = decode_mvdv(s, avctx, frame); |
| } |
| |
| if (ret < 0) |
| return ret; |
| key = ret; |
| |
| if ((ret = av_frame_ref(data, s->frame)) < 0) |
| return ret; |
| |
| frame->pict_type = key ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P; |
| frame->key_frame = key; |
| *got_frame = 1; |
| |
| return avpkt->size; |
| } |
| |
| static av_cold int decode_init(AVCodecContext *avctx) |
| { |
| MidiVidContext *s = avctx->priv_data; |
| int ret = av_image_check_size(avctx->width, avctx->height, 0, avctx); |
| |
| if (avctx->width & 3 || avctx->height & 3) |
| ret = AVERROR_INVALIDDATA; |
| |
| if (ret < 0) { |
| av_log(avctx, AV_LOG_ERROR, "Invalid image size %dx%d.\n", |
| avctx->width, avctx->height); |
| return ret; |
| } |
| |
| avctx->pix_fmt = AV_PIX_FMT_YUV444P; |
| |
| s->frame = av_frame_alloc(); |
| if (!s->frame) |
| return AVERROR(ENOMEM); |
| s->skip = av_calloc(avctx->width >> 1, avctx->height >> 1); |
| if (!s->skip) |
| return AVERROR(ENOMEM); |
| |
| return 0; |
| } |
| |
| static void decode_flush(AVCodecContext *avctx) |
| { |
| MidiVidContext *s = avctx->priv_data; |
| |
| av_frame_unref(s->frame); |
| } |
| |
| static av_cold int decode_close(AVCodecContext *avctx) |
| { |
| MidiVidContext *s = avctx->priv_data; |
| |
| av_frame_free(&s->frame); |
| av_freep(&s->uncompressed); |
| av_freep(&s->skip); |
| |
| return 0; |
| } |
| |
| AVCodec ff_mvdv_decoder = { |
| .name = "mvdv", |
| .long_name = NULL_IF_CONFIG_SMALL("MidiVid VQ"), |
| .type = AVMEDIA_TYPE_VIDEO, |
| .id = AV_CODEC_ID_MVDV, |
| .priv_data_size = sizeof(MidiVidContext), |
| .init = decode_init, |
| .decode = decode_frame, |
| .flush = decode_flush, |
| .close = decode_close, |
| .capabilities = AV_CODEC_CAP_DR1, |
| .caps_internal = FF_CODEC_CAP_INIT_CLEANUP, |
| }; |