X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libavcodec%2Frtjpeg.c;h=67eeff8f4a6152249516930b9dd81201f4a4ac28;hb=5f74bd31a9bd1ac7655103b11743c12d38e0419f;hp=2736807439d7003f8ca1fcc542737c53a1366ed9;hpb=0766291a669281f556d7a0b32e8a920650dd93db;p=ffmpeg diff --git a/libavcodec/rtjpeg.c b/libavcodec/rtjpeg.c index 2736807439d..67eeff8f4a6 100644 --- a/libavcodec/rtjpeg.c +++ b/libavcodec/rtjpeg.c @@ -2,48 +2,48 @@ * RTJpeg decoding functions * Copyright (c) 2006 Reimar Doeffinger * - * This file is part of FFmpeg. + * This file is part of Libav. * - * FFmpeg is free software; you can redistribute it and/or + * 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. * - * FFmpeg is distributed in the hope that it will be useful, + * 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 FFmpeg; if not, write to the Free Software + * License along with Libav; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include "libavutil/common.h" #include "get_bits.h" -#include "dsputil.h" #include "rtjpeg.h" #define PUT_COEFF(c) \ i = scan[coeff--]; \ block[i] = (c) * quant[i]; -//! aligns the bitstream to the give power of two +/// aligns the bitstream to the given power of two #define ALIGN(a) \ n = (-get_bits_count(gb)) & (a - 1); \ if (n) {skip_bits(gb, n);} /** - * \brief read one block from stream - * \param gb contains stream data - * \param block where data is written to - * \param scan array containing the mapping stream address -> block position - * \param quant quantization factors + * @brief read one block from stream + * @param gb contains stream data + * @param block where data is written to + * @param scan array containing the mapping stream address -> block position + * @param quant quantization factors + * @return 0 means the block is not coded, < 0 means an error occurred. * * Note: GetBitContext is used to make the code simpler, since all data is * aligned this could be done faster in a different way, e.g. as it is done * in MPlayer libmpcodecs/native/rtjpegn.c. */ -static inline int get_block(GetBitContext *gb, DCTELEM *block, const uint8_t *scan, +static inline int get_block(GetBitContext *gb, int16_t *block, const uint8_t *scan, const uint32_t *quant) { int coeff, i, n; int8_t ac; @@ -55,9 +55,12 @@ static inline int get_block(GetBitContext *gb, DCTELEM *block, const uint8_t *sc // number of non-zero coefficients coeff = get_bits(gb, 6); + if (get_bits_left(gb) < (coeff << 1)) + return AVERROR_INVALIDDATA; + // normally we would only need to clear the (63 - coeff) last values, // but since we do not know where they are we just clear the whole block - memset(block, 0, 64 * sizeof(DCTELEM)); + memset(block, 0, 64 * sizeof(int16_t)); // 2 bits per coefficient while (coeff) { @@ -69,6 +72,8 @@ static inline int get_block(GetBitContext *gb, DCTELEM *block, const uint8_t *sc // 4 bits per coefficient ALIGN(4); + if (get_bits_left(gb) < (coeff << 2)) + return AVERROR_INVALIDDATA; while (coeff) { ac = get_sbits(gb, 4); if (ac == -8) @@ -78,6 +83,8 @@ static inline int get_block(GetBitContext *gb, DCTELEM *block, const uint8_t *sc // 8 bits per coefficient ALIGN(8); + if (get_bits_left(gb) < (coeff << 3)) + return AVERROR_INVALIDDATA; while (coeff) { ac = get_sbits(gb, 8); PUT_COEFF(ac); @@ -88,42 +95,46 @@ static inline int get_block(GetBitContext *gb, DCTELEM *block, const uint8_t *sc } /** - * \brief decode one rtjpeg YUV420 frame - * \param c context, must be initialized via rtjpeg_decode_init - * \param f AVFrame to place decoded frame into. If parts of the frame + * @brief decode one rtjpeg YUV420 frame + * @param c context, must be initialized via ff_rtjpeg_decode_init + * @param f AVFrame to place decoded frame into. If parts of the frame * are not coded they are left unchanged, so consider initializing it - * \param buf buffer containing input data - * \param buf_size length of input data in bytes - * \return number of bytes consumed from the input buffer + * @param buf buffer containing input data + * @param buf_size length of input data in bytes + * @return number of bytes consumed from the input buffer */ -int rtjpeg_decode_frame_yuv420(RTJpegContext *c, AVFrame *f, - const uint8_t *buf, int buf_size) { +int ff_rtjpeg_decode_frame_yuv420(RTJpegContext *c, AVFrame *f, + const uint8_t *buf, int buf_size) { GetBitContext gb; int w = c->w / 16, h = c->h / 16; - int x, y; + int x, y, ret; uint8_t *y1 = f->data[0], *y2 = f->data[0] + 8 * f->linesize[0]; uint8_t *u = f->data[1], *v = f->data[2]; - init_get_bits(&gb, buf, buf_size * 8); + + if ((ret = init_get_bits8(&gb, buf, buf_size)) < 0) + return ret; + for (y = 0; y < h; y++) { for (x = 0; x < w; x++) { - DCTELEM *block = c->block; - if (get_block(&gb, block, c->scan, c->lquant)) - c->dsp->idct_put(y1, f->linesize[0], block); +#define BLOCK(quant, dst, stride) do { \ + int res = get_block(&gb, block, c->scan, quant); \ + if (res < 0) \ + return res; \ + if (res > 0) \ + c->idsp.idct_put(dst, stride, block); \ +} while (0) + int16_t *block = c->block; + BLOCK(c->lquant, y1, f->linesize[0]); y1 += 8; - if (get_block(&gb, block, c->scan, c->lquant)) - c->dsp->idct_put(y1, f->linesize[0], block); + BLOCK(c->lquant, y1, f->linesize[0]); y1 += 8; - if (get_block(&gb, block, c->scan, c->lquant)) - c->dsp->idct_put(y2, f->linesize[0], block); + BLOCK(c->lquant, y2, f->linesize[0]); y2 += 8; - if (get_block(&gb, block, c->scan, c->lquant)) - c->dsp->idct_put(y2, f->linesize[0], block); + BLOCK(c->lquant, y2, f->linesize[0]); y2 += 8; - if (get_block(&gb, block, c->scan, c->cquant)) - c->dsp->idct_put(u, f->linesize[1], block); + BLOCK(c->cquant, u, f->linesize[1]); u += 8; - if (get_block(&gb, block, c->scan, c->cquant)) - c->dsp->idct_put(v, f->linesize[2], block); + BLOCK(c->cquant, v, f->linesize[2]); v += 8; } y1 += 2 * 8 * (f->linesize[0] - w); @@ -135,31 +146,38 @@ int rtjpeg_decode_frame_yuv420(RTJpegContext *c, AVFrame *f, } /** - * \brief initialize an RTJpegContext, may be called multiple times - * \param c context to initialize - * \param dsp specifies the idct to use for decoding - * \param width width of image, will be rounded down to the nearest multiple + * @brief initialize an RTJpegContext, may be called multiple times + * @param c context to initialize + * @param width width of image, will be rounded down to the nearest multiple * of 16 for decoding - * \param height height of image, will be rounded down to the nearest multiple + * @param height height of image, will be rounded down to the nearest multiple * of 16 for decoding - * \param lquant luma quantization table to use - * \param cquant chroma quantization table to use + * @param lquant luma quantization table to use + * @param cquant chroma quantization table to use */ -void rtjpeg_decode_init(RTJpegContext *c, DSPContext *dsp, - int width, int height, - const uint32_t *lquant, const uint32_t *cquant) { +void ff_rtjpeg_decode_init(RTJpegContext *c, int width, int height, + const uint32_t *lquant, const uint32_t *cquant) { int i; - c->dsp = dsp; for (i = 0; i < 64; i++) { - int z = ff_zigzag_direct[i]; - int p = c->dsp->idct_permutation[i]; - z = ((z << 3) | (z >> 3)) & 63; // rtjpeg uses a transposed variant - - // permute the scan and quantization tables for the chosen idct - c->scan[i] = c->dsp->idct_permutation[z]; + int p = c->idsp.idct_permutation[i]; c->lquant[p] = lquant[i]; c->cquant[p] = cquant[i]; } c->w = width; c->h = height; } + +void ff_rtjpeg_init(RTJpegContext *c, AVCodecContext *avctx) +{ + int i; + + ff_idctdsp_init(&c->idsp, avctx); + + for (i = 0; i < 64; i++) { + int z = ff_zigzag_direct[i]; + z = ((z << 3) | (z >> 3)) & 63; // rtjpeg uses a transposed variant + + // permute the scan and quantization tables for the chosen idct + c->scan[i] = c->idsp.idct_permutation[z]; + } +}