/* * QPEG codec * Copyright (c) 2004 Konstantin Shishkov * * This file is part of Libav. * * Libav 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. * * Libav 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 Libav; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /** * @file * QPEG codec. */ #include "avcodec.h" #include "bytestream.h" #include "internal.h" typedef struct QpegContext{ AVCodecContext *avctx; AVFrame *pic; uint8_t *refdata; uint32_t pal[256]; GetByteContext buffer; } QpegContext; static void qpeg_decode_intra(QpegContext *qctx, uint8_t *dst, int stride, int width, int height) { int i; int code; int c0, c1; int run, copy; int filled = 0; int rows_to_go; rows_to_go = height; height--; dst = dst + height * stride; while ((bytestream2_get_bytes_left(&qctx->buffer) > 0) && (rows_to_go > 0)) { code = bytestream2_get_byte(&qctx->buffer); run = copy = 0; if(code == 0xFC) /* end-of-picture code */ break; if(code >= 0xF8) { /* very long run */ c0 = bytestream2_get_byte(&qctx->buffer); c1 = bytestream2_get_byte(&qctx->buffer); run = ((code & 0x7) << 16) + (c0 << 8) + c1 + 2; } else if (code >= 0xF0) { /* long run */ c0 = bytestream2_get_byte(&qctx->buffer); run = ((code & 0xF) << 8) + c0 + 2; } else if (code >= 0xE0) { /* short run */ run = (code & 0x1F) + 2; } else if (code >= 0xC0) { /* very long copy */ c0 = bytestream2_get_byte(&qctx->buffer); c1 = bytestream2_get_byte(&qctx->buffer); copy = ((code & 0x3F) << 16) + (c0 << 8) + c1 + 1; } else if (code >= 0x80) { /* long copy */ c0 = bytestream2_get_byte(&qctx->buffer); copy = ((code & 0x7F) << 8) + c0 + 1; } else { /* short copy */ copy = code + 1; } /* perform actual run or copy */ if(run) { int p; p = bytestream2_get_byte(&qctx->buffer); for(i = 0; i < run; i++) { dst[filled++] = p; if (filled >= width) { filled = 0; dst -= stride; rows_to_go--; if(rows_to_go <= 0) break; } } } else { for(i = 0; i < copy; i++) { dst[filled++] = bytestream2_get_byte(&qctx->buffer); if (filled >= width) { filled = 0; dst -= stride; rows_to_go--; if(rows_to_go <= 0) break; } } } } } static const int qpeg_table_h[16] = { 0x00, 0x20, 0x20, 0x20, 0x18, 0x10, 0x10, 0x20, 0x10, 0x08, 0x18, 0x08, 0x08, 0x18, 0x10, 0x04}; static const int qpeg_table_w[16] = { 0x00, 0x20, 0x18, 0x08, 0x18, 0x10, 0x20, 0x10, 0x08, 0x10, 0x20, 0x20, 0x08, 0x10, 0x18, 0x04}; /* Decodes delta frames */ static void qpeg_decode_inter(QpegContext *qctx, uint8_t *dst, int stride, int width, int height, int delta, const uint8_t *ctable, uint8_t *refdata) { int i, j; int code; int filled = 0; int orig_height; /* copy prev frame */ for(i = 0; i < height; i++) memcpy(refdata + (i * width), dst + (i * stride), width); orig_height = height; height--; dst = dst + height * stride; while ((bytestream2_get_bytes_left(&qctx->buffer) > 0) && (height >= 0)) { code = bytestream2_get_byte(&qctx->buffer); if(delta) { /* motion compensation */ while((code & 0xF0) == 0xF0) { if(delta == 1) { int me_idx; int me_w, me_h, me_x, me_y; uint8_t *me_plane; int corr, val; /* get block size by index */ me_idx = code & 0xF; me_w = qpeg_table_w[me_idx]; me_h = qpeg_table_h[me_idx]; /* extract motion vector */ corr = bytestream2_get_byte(&qctx->buffer); val = corr >> 4; if(val > 7) val -= 16; me_x = val; val = corr & 0xF; if(val > 7) val -= 16; me_y = val; /* check motion vector */ if ((me_x + filled < 0) || (me_x + me_w + filled > width) || (height - me_y - me_h < 0) || (height - me_y > orig_height) || (filled + me_w > width) || (height - me_h < 0)) av_log(NULL, AV_LOG_ERROR, "Bogus motion vector (%i,%i), block size %ix%i at %i,%i\n", me_x, me_y, me_w, me_h, filled, height); else { /* do motion compensation */ me_plane = refdata + (filled + me_x) + (height - me_y) * width; for(j = 0; j < me_h; j++) { for(i = 0; i < me_w; i++) dst[filled + i - (j * stride)] = me_plane[i - (j * width)]; } } } code = bytestream2_get_byte(&qctx->buffer); } } if(code == 0xE0) /* end-of-picture code */ break; if(code > 0xE0) { /* run code: 0xE1..0xFF */ int p; code &= 0x1F; p = bytestream2_get_byte(&qctx->buffer); for(i = 0; i <= code; i++) { dst[filled++] = p; if(filled >= width) { filled = 0; dst -= stride; height--; if (height < 0) break; } } } else if(code >= 0xC0) { /* copy code: 0xC0..0xDF */ code &= 0x1F; for(i = 0; i <= code; i++) { dst[filled++] = bytestream2_get_byte(&qctx->buffer); if(filled >= width) { filled = 0; dst -= stride; height--; if (height < 0) break; } } } else if(code >= 0x80) { /* skip code: 0x80..0xBF */ int skip; code &= 0x3F; /* codes 0x80 and 0x81 are actually escape codes, skip value minus constant is in the next byte */ if(!code) skip = bytestream2_get_byte(&qctx->buffer) + 64; else if(code == 1) skip = bytestream2_get_byte(&qctx->buffer) + 320; else skip = code; filled += skip; while( filled >= width) { filled -= width; dst -= stride; height--; if(height < 0) break; } } else { /* zero code treated as one-pixel skip */ if(code) { dst[filled++] = ctable[code & 0x7F]; } else filled++; if(filled >= width) { filled = 0; dst -= stride; height--; } } } } static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt) { uint8_t ctable[128]; QpegContext * const a = avctx->priv_data; AVFrame * const p = a->pic; uint8_t* outdata; int delta, ret; const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL); if (avpkt->size < 0x86) { av_log(avctx, AV_LOG_ERROR, "Packet is too small\n"); return AVERROR_INVALIDDATA; } bytestream2_init(&a->buffer, avpkt->data, avpkt->size); if ((ret = ff_reget_buffer(avctx, p)) < 0) { av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n"); return ret; } outdata = p->data[0]; bytestream2_skip(&a->buffer, 4); bytestream2_get_buffer(&a->buffer, ctable, 128); bytestream2_skip(&a->buffer, 1); delta = bytestream2_get_byte(&a->buffer); if(delta == 0x10) { qpeg_decode_intra(a, outdata, p->linesize[0], avctx->width, avctx->height); } else { qpeg_decode_inter(a, outdata, p->linesize[0], avctx->width, avctx->height, delta, ctable, a->refdata); } /* make the palette available on the way out */ if (pal) { p->palette_has_changed = 1; memcpy(a->pal, pal, AVPALETTE_SIZE); } memcpy(p->data[1], a->pal, AVPALETTE_SIZE); if ((ret = av_frame_ref(data, p)) < 0) return ret; *got_frame = 1; return avpkt->size; } static av_cold int decode_end(AVCodecContext *avctx) { QpegContext * const a = avctx->priv_data; av_frame_free(&a->pic); av_free(a->refdata); return 0; } static av_cold int decode_init(AVCodecContext *avctx){ QpegContext * const a = avctx->priv_data; a->avctx = avctx; avctx->pix_fmt= AV_PIX_FMT_PAL8; a->refdata = av_malloc(avctx->width * avctx->height); a->pic = av_frame_alloc(); if (!a->pic) { decode_end(avctx); return AVERROR(ENOMEM); } return 0; } AVCodec ff_qpeg_decoder = { .name = "qpeg", .long_name = NULL_IF_CONFIG_SMALL("Q-team QPEG"), .type = AVMEDIA_TYPE_VIDEO, .id = AV_CODEC_ID_QPEG, .priv_data_size = sizeof(QpegContext), .init = decode_init, .close = decode_end, .decode = decode_frame, .capabilities = AV_CODEC_CAP_DR1, };