/* * LEAD MCMP decoder * * Copyright (c) 2023 Peter Ross * * 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 "blockdsp.h" #include "codec_internal.h" #include "copy_block.h" #include "decode.h" #include "get_bits.h" #include "idctdsp.h" #include "jpegquanttables.h" #include "jpegtables.h" #include "leaddata.h" #include "libavutil/mem_internal.h" #include "libavutil/thread.h" #define LUMA_DC_BITS 9 #define CHROMA_DC_BITS 11 #define LUMA_AC_BITS 10 #define CHROMA_AC_BITS 10 static VLC luma_dc_vlc; static VLC chroma_dc_vlc; static VLC luma_ac_vlc; static VLC chroma_ac_vlc; static av_cold void lead_init_static_data(void) { VLC_INIT_STATIC_FROM_LENGTHS(&luma_dc_vlc, LUMA_DC_BITS, FF_ARRAY_ELEMS(luma_dc_len), luma_dc_len, 1, 0, 0, 0, 0, 0, 1 << LUMA_DC_BITS); VLC_INIT_STATIC_FROM_LENGTHS(&chroma_dc_vlc, CHROMA_DC_BITS, FF_ARRAY_ELEMS(chroma_dc_len), chroma_dc_len, 1, 0, 0, 0, 0, 0, 1 << CHROMA_DC_BITS); VLC_INIT_STATIC_FROM_LENGTHS(&luma_ac_vlc, LUMA_AC_BITS, FF_ARRAY_ELEMS(luma_ac_len), luma_ac_len, 1, ff_mjpeg_val_ac_luminance, 1, 1, 0, 0, 1160); VLC_INIT_STATIC_FROM_LENGTHS(&chroma_ac_vlc, CHROMA_AC_BITS, FF_ARRAY_ELEMS(chroma_ac_len), chroma_ac_len, 1, ff_mjpeg_val_ac_chrominance, 1, 1, 0, 0, 1160); } typedef struct LeadContext { uint8_t *bitstream_buf; unsigned int bitstream_buf_size; BlockDSPContext bdsp; IDCTDSPContext idsp; uint8_t permutated_scantable[64]; } LeadContext; static av_cold int lead_decode_init(AVCodecContext * avctx) { static AVOnce init_static_once = AV_ONCE_INIT; LeadContext *s = avctx->priv_data; if (avctx->extradata_size < 20) return AVERROR_INVALIDDATA; ff_blockdsp_init(&s->bdsp); ff_idctdsp_init(&s->idsp, avctx); ff_permute_scantable(s->permutated_scantable, ff_zigzag_direct, s->idsp.idct_permutation); ff_thread_once(&init_static_once, lead_init_static_data); return 0; } static void calc_dequant(uint16_t * dequant, const uint8_t * quant_tbl, int q) { for (int i = 0; i < 64; i++) dequant[i] = av_clip(q * quant_tbl[ff_zigzag_direct[i]] / 50, 2, 32767); } static int decode_block(LeadContext * s, GetBitContext * gb, const VLCElem * dc_table, int dc_bits, const VLCElem * ac_table, int ac_bits, int16_t * dc_pred, const uint16_t * dequant, uint8_t * dst, int stride) { DECLARE_ALIGNED(32, int16_t, block)[64]; int size; s->bdsp.clear_block(block); if (get_bits_left(gb) <= 0) return AVERROR_INVALIDDATA; size = get_vlc2(gb, dc_table, dc_bits, 1); if (size < 0) return AVERROR_INVALIDDATA; if (size) *dc_pred += get_xbits(gb, size); block[0] = (1 << 10) + *dc_pred * dequant[0]; for (int i = 1; i < 64; i++) { int symbol = get_vlc2(gb, ac_table, ac_bits, 2); if (symbol < 0) return AVERROR_INVALIDDATA; if (!symbol) break; i += symbol >> 4; if (i >= 64) return AVERROR_INVALIDDATA; size = symbol & 0xF; if (size) block[s->permutated_scantable[i]] = get_xbits(gb, size) * dequant[i]; } s->idsp.idct_put(dst, stride, block); return 0; } static int lead_decode_frame(AVCodecContext *avctx, AVFrame * frame, int * got_frame, AVPacket * avpkt) { LeadContext *s = avctx->priv_data; const uint8_t * buf = avpkt->data; int ret, format, yuv20p_half = 0, fields = 1, q, size; GetBitContext gb; int16_t dc_pred[3] = {0, 0, 0}; uint16_t dequant[2][64]; if (avpkt->size < 8) return AVERROR_INVALIDDATA; format = AV_RL16(buf + 4); switch(format) { case 0x8000: yuv20p_half = 1; // fall-through case 0x1000: avctx->pix_fmt = AV_PIX_FMT_YUV420P; break; case 0x2000: avctx->pix_fmt = AV_PIX_FMT_YUV444P; break; case 0x2006: avctx->pix_fmt = AV_PIX_FMT_YUV444P; fields = 2; break; default: avpriv_request_sample(avctx, "unsupported format 0x%x", format); return AVERROR_PATCHWELCOME; } q = AV_RL16(buf + 6); calc_dequant(dequant[0], ff_mjpeg_std_luminance_quant_tbl, q); calc_dequant(dequant[1], ff_mjpeg_std_chrominance_quant_tbl, q); if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) return ret; frame->flags |= AV_FRAME_FLAG_KEY; frame->pict_type = AV_PICTURE_TYPE_I; av_fast_padded_malloc(&s->bitstream_buf, &s->bitstream_buf_size, avpkt->size - 8); if (!s->bitstream_buf) return AVERROR(ENOMEM); size = 0; for (int i = 8; i < avpkt->size; i++) { int src = buf[i] ^ 0x80; s->bitstream_buf[size++] = src; if (src == 0xFF && i + 1 < avpkt->size && (buf[i + 1] ^ 0x80) == 0x00) i++; } init_get_bits8(&gb, s->bitstream_buf, size); if (avctx->pix_fmt == AV_PIX_FMT_YUV420P) { for (int mb_y = 0; mb_y < avctx->height / 16; mb_y++) for (int mb_x = 0; mb_x < avctx->width / 16; mb_x++) for (int b = 0; b < (yuv20p_half ? 4 : 6); b++) { int luma_block = yuv20p_half ? 2 : 4; const VLCElem * dc_vlc = b < luma_block ? luma_dc_vlc.table : chroma_dc_vlc.table; int dc_bits = b < luma_block ? LUMA_DC_BITS : CHROMA_DC_BITS; const VLCElem * ac_vlc = b < luma_block ? luma_ac_vlc.table : chroma_ac_vlc.table; int ac_bits = b < luma_block ? LUMA_AC_BITS : CHROMA_AC_BITS; int plane = b < luma_block ? 0 : b - (yuv20p_half ? 1 : 3); int x, y; if (b < luma_block) { y = 16*mb_y + 8*(b >> 1); x = 16*mb_x + 8*(b & 1); } else { y = 8*mb_y; x = 8*mb_x; } ret = decode_block(s, &gb, dc_vlc, dc_bits, ac_vlc, ac_bits, dc_pred + plane, dequant[!(b < 4)], frame->data[plane] + y*frame->linesize[plane] + x, (yuv20p_half && b < 2 ? 2 : 1) * frame->linesize[plane]); if (ret < 0) return ret; if (yuv20p_half && b < 2) copy_block8(frame->data[plane] + (y + 1)*frame->linesize[plane] + x, frame->data[plane] + y*frame->linesize[plane] + x, 2*frame->linesize[plane], 2*frame->linesize[plane], 8); } } else { for (int f = 0; f < fields; f++) for (int j = 0; j < avctx->height / fields / 8; j++) for (int i = 0; i < avctx->width / 8; i++) for (int plane = 0; plane < 3; plane++) { const VLCElem * dc_vlc = !plane ? luma_dc_vlc.table : chroma_dc_vlc.table; int dc_bits = !plane ? LUMA_DC_BITS : CHROMA_DC_BITS; const VLCElem * ac_vlc = !plane ? luma_ac_vlc.table : chroma_ac_vlc.table; int ac_bits = !plane ? LUMA_AC_BITS : CHROMA_AC_BITS; ret = decode_block(s, &gb, dc_vlc, dc_bits, ac_vlc, ac_bits, dc_pred + plane, dequant[!!plane], frame->data[plane] + (f + 8*j*fields)*frame->linesize[plane] + 8*i, fields * frame->linesize[plane]); if (ret < 0) return ret; } } *got_frame = 1; return avpkt->size; } static av_cold int lead_decode_end(AVCodecContext * avctx) { LeadContext *s = avctx->priv_data; av_freep(&s->bitstream_buf); return 0; } const FFCodec ff_lead_decoder = { .p.name = "lead", CODEC_LONG_NAME("LEAD MCMP"), .p.type = AVMEDIA_TYPE_VIDEO, .p.id = AV_CODEC_ID_LEAD, .priv_data_size = sizeof(LeadContext), .init = lead_decode_init, .close = lead_decode_end, FF_CODEC_DECODE_CB(lead_decode_frame), .p.capabilities = AV_CODEC_CAP_DR1, .caps_internal = FF_CODEC_CAP_INIT_CLEANUP, };