/* * Apple Pixlet decoder * Copyright (c) 2016 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 <stdint.h> #include "libavutil/imgutils.h" #include "libavutil/intmath.h" #include "libavutil/opt.h" #include "avcodec.h" #include "bytestream.h" #include "get_bits.h" #include "internal.h" #include "thread.h" #include "unary.h" #define NB_LEVELS 4 #define PIXLET_MAGIC 0xDEADBEEF #define H 0 #define V 1 typedef struct SubBand { unsigned width, height; unsigned size; unsigned x, y; } SubBand; typedef struct PixletContext { AVClass *class; GetByteContext gb; GetBitContext bc; int levels; int depth; int w, h; int16_t *filter[2]; int16_t *prediction; int64_t scaling[4][2][NB_LEVELS]; uint16_t lut[65536]; SubBand band[4][NB_LEVELS * 3 + 1]; } PixletContext; static av_cold int pixlet_init(AVCodecContext *avctx) { avctx->pix_fmt = AV_PIX_FMT_YUV420P16; avctx->color_range = AVCOL_RANGE_JPEG; return 0; } static void free_buffers(AVCodecContext *avctx) { PixletContext *ctx = avctx->priv_data; av_freep(&ctx->filter[0]); av_freep(&ctx->filter[1]); av_freep(&ctx->prediction); } static av_cold int pixlet_close(AVCodecContext *avctx) { PixletContext *ctx = avctx->priv_data; free_buffers(avctx); ctx->w = 0; ctx->h = 0; return 0; } static int init_decoder(AVCodecContext *avctx) { PixletContext *ctx = avctx->priv_data; int i, plane; ctx->filter[0] = av_malloc_array(ctx->h, sizeof(int16_t)); ctx->filter[1] = av_malloc_array(FFMAX(ctx->h, ctx->w) + 16, sizeof(int16_t)); ctx->prediction = av_malloc_array((ctx->w >> NB_LEVELS), sizeof(int16_t)); if (!ctx->filter[0] || !ctx->filter[1] || !ctx->prediction) return AVERROR(ENOMEM); for (plane = 0; plane < 3; plane++) { unsigned shift = plane > 0; unsigned w = ctx->w >> shift; unsigned h = ctx->h >> shift; ctx->band[plane][0].width = w >> NB_LEVELS; ctx->band[plane][0].height = h >> NB_LEVELS; ctx->band[plane][0].size = (w >> NB_LEVELS) * (h >> NB_LEVELS); for (i = 0; i < NB_LEVELS * 3; i++) { unsigned scale = ctx->levels - (i / 3); ctx->band[plane][i + 1].width = w >> scale; ctx->band[plane][i + 1].height = h >> scale; ctx->band[plane][i + 1].size = (w >> scale) * (h >> scale); ctx->band[plane][i + 1].x = (w >> scale) * (((i + 1) % 3) != 2); ctx->band[plane][i + 1].y = (h >> scale) * (((i + 1) % 3) != 1); } } return 0; } static int read_low_coeffs(AVCodecContext *avctx, int16_t *dst, int size, int width, ptrdiff_t stride) { PixletContext *ctx = avctx->priv_data; GetBitContext *bc = &ctx->bc; unsigned cnt1, nbits, k, j = 0, i = 0; int64_t value, state = 3; int rlen, escape, flag = 0; while (i < size) { nbits = FFMIN(ff_clz((state >> 8) + 3) ^ 0x1F, 14); cnt1 = get_unary(bc, 0, 8); if (cnt1 < 8) { value = show_bits(bc, nbits); if (value <= 1) { skip_bits(bc, nbits - 1); escape = ((1 << nbits) - 1) * cnt1; } else { skip_bits(bc, nbits); escape = value + ((1 << nbits) - 1) * cnt1 - 1; } } else { escape = get_bits(bc, 16); } value = -((escape + flag) & 1) | 1; dst[j++] = value * ((escape + flag + 1) >> 1); i++; if (j == width) { j = 0; dst += stride; } state = 120 * (escape + flag) + state - (120 * state >> 8); flag = 0; if (state * 4ULL > 0xFF || i >= size) continue; nbits = ((state + 8) >> 5) + (state ? ff_clz(state) : 32) - 24; escape = av_mod_uintp2(16383, nbits); cnt1 = get_unary(bc, 0, 8); if (cnt1 > 7) { rlen = get_bits(bc, 16); } else { value = show_bits(bc, nbits); if (value > 1) { skip_bits(bc, nbits); rlen = value + escape * cnt1 - 1; } else { skip_bits(bc, nbits - 1); rlen = escape * cnt1; } } if (rlen > size - i) return AVERROR_INVALIDDATA; i += rlen; for (k = 0; k < rlen; k++) { dst[j++] = 0; if (j == width) { j = 0; dst += stride; } } state = 0; flag = rlen < 0xFFFF ? 1 : 0; } align_get_bits(bc); return get_bits_count(bc) >> 3; } static int read_high_coeffs(AVCodecContext *avctx, uint8_t *src, int16_t *dst, int size, int c, int a, int d, int width, ptrdiff_t stride) { PixletContext *ctx = avctx->priv_data; GetBitContext *bc = &ctx->bc; unsigned cnt1, shbits, rlen, nbits, length, i = 0, j = 0, k; int ret, escape, pfx, value, yflag, xflag, flag = 0; int64_t state = 3, tmp; ret = init_get_bits8(bc, src, bytestream2_get_bytes_left(&ctx->gb)); if (ret < 0) return ret; if (a ^ (a >> 31)) { nbits = 33 - ff_clz(a ^ (a >> 31)); if (nbits > 16) return AVERROR_INVALIDDATA; } else { nbits = 1; } length = 25 - nbits; while (i < size) { if (((state >> 8) + 3) & 0xFFFFFFF) value = ff_clz((state >> 8) + 3) ^ 0x1F; else value = -1; cnt1 = get_unary(bc, 0, length); if (cnt1 >= length) { cnt1 = get_bits(bc, nbits); } else { pfx = 14 + ((((uint64_t)(value - 14)) >> 32) & (value - 14)); if (pfx < 1 || pfx > 25) return AVERROR_INVALIDDATA; cnt1 *= (1 << pfx) - 1; shbits = show_bits(bc, pfx); if (shbits <= 1) { skip_bits(bc, pfx - 1); } else { skip_bits(bc, pfx); cnt1 += shbits - 1; } } xflag = flag + cnt1; yflag = xflag; if (flag + cnt1 == 0) { value = 0; } else { xflag &= 1u; tmp = (int64_t)c * ((yflag + 1) >> 1) + (c >> 1); value = xflag + (tmp ^ -xflag); } i++; dst[j++] = value; if (j == width) { j = 0; dst += stride; } state += (int64_t)d * (uint64_t)yflag - ((int64_t)(d * (uint64_t)state) >> 8); flag = 0; if ((uint64_t)state > 0xFF / 4 || i >= size) continue; pfx = ((state + 8) >> 5) + (state ? ff_clz(state) : 32) - 24; escape = av_mod_uintp2(16383, pfx); cnt1 = get_unary(bc, 0, 8); if (cnt1 < 8) { if (pfx < 1 || pfx > 25) return AVERROR_INVALIDDATA; value = show_bits(bc, pfx); if (value > 1) { skip_bits(bc, pfx); rlen = value + escape * cnt1 - 1; } else { skip_bits(bc, pfx - 1); rlen = escape * cnt1; } } else { if (get_bits1(bc)) value = get_bits(bc, 16); else value = get_bits(bc, 8); rlen = value + 8 * escape; } if (rlen > 0xFFFF || i + rlen > size) return AVERROR_INVALIDDATA; i += rlen; for (k = 0; k < rlen; k++) { dst[j++] = 0; if (j == width) { j = 0; dst += stride; } } state = 0; flag = rlen < 0xFFFF ? 1 : 0; } align_get_bits(bc); return get_bits_count(bc) >> 3; } static int read_highpass(AVCodecContext *avctx, uint8_t *ptr, int plane, AVFrame *frame) { PixletContext *ctx = avctx->priv_data; ptrdiff_t stride = frame->linesize[plane] / 2; int i, ret; for (i = 0; i < ctx->levels * 3; i++) { int32_t a = bytestream2_get_be32(&ctx->gb); int32_t b = bytestream2_get_be32(&ctx->gb); int32_t c = bytestream2_get_be32(&ctx->gb); int32_t d = bytestream2_get_be32(&ctx->gb); int16_t *dest = (int16_t *)frame->data[plane] + ctx->band[plane][i + 1].x + ctx->band[plane][i + 1].y * stride; unsigned size = ctx->band[plane][i + 1].size; uint32_t magic = bytestream2_get_be32(&ctx->gb); if (magic != PIXLET_MAGIC) { av_log(avctx, AV_LOG_ERROR, "wrong magic number: 0x%08"PRIX32" for plane %d, band %d\n", magic, plane, i); return AVERROR_INVALIDDATA; } if (a == INT32_MIN) return AVERROR_INVALIDDATA; ret = read_high_coeffs(avctx, ptr + bytestream2_tell(&ctx->gb), dest, size, c, (b >= FFABS(a)) ? b : a, d, ctx->band[plane][i + 1].width, stride); if (ret < 0) { av_log(avctx, AV_LOG_ERROR, "error in highpass coefficients for plane %d, band %d\n", plane, i); return ret; } bytestream2_skip(&ctx->gb, ret); } return 0; } static void lowpass_prediction(int16_t *dst, int16_t *pred, int width, int height, ptrdiff_t stride) { int16_t val; int i, j; memset(pred, 0, width * sizeof(*pred)); for (i = 0; i < height; i++) { val = pred[0] + dst[0]; dst[0] = pred[0] = val; for (j = 1; j < width; j++) { val = pred[j] + dst[j]; dst[j] = pred[j] = val; dst[j] += dst[j-1]; } dst += stride; } } static void filterfn(int16_t *dest, int16_t *tmp, unsigned size, int64_t scale) { int16_t *low, *high, *ll, *lh, *hl, *hh; int hsize, i, j; int64_t value; hsize = size >> 1; low = tmp + 4; high = &low[hsize + 8]; memcpy(low, dest, size); memcpy(high, dest + hsize, size); ll = &low[hsize]; lh = &low[hsize]; hl = &high[hsize]; hh = hl; for (i = 4, j = 2; i; i--, j++, ll--, hh++, lh++, hl--) { low[i - 5] = low[j - 1]; lh[0] = ll[-1]; high[i - 5] = high[j - 2]; hh[0] = hl[-2]; } for (i = 0; i < hsize; i++) { value = (int64_t) low [i + 1] * -INT64_C(325392907) + (int64_t) low [i + 0] * INT64_C(3687786320) + (int64_t) low [i - 1] * -INT64_C(325392907) + (int64_t) high[i + 0] * INT64_C(1518500249) + (int64_t) high[i - 1] * INT64_C(1518500249); dest[i * 2] = av_clip_int16(((value >> 32) * scale) >> 32); } for (i = 0; i < hsize; i++) { value = (int64_t) low [i + 2] * -INT64_C(65078576) + (int64_t) low [i + 1] * INT64_C(1583578880) + (int64_t) low [i + 0] * INT64_C(1583578880) + (int64_t) low [i - 1] * -INT64_C(65078576) + (int64_t) high[i + 1] * INT64_C(303700064) + (int64_t) high[i + 0] * -INT64_C(3644400640) + (int64_t) high[i - 1] * INT64_C(303700064); dest[i * 2 + 1] = av_clip_int16(((value >> 32) * scale) >> 32); } } static void reconstruction(AVCodecContext *avctx, int16_t *dest, unsigned width, unsigned height, ptrdiff_t stride, int64_t *scaling_h, int64_t *scaling_v) { PixletContext *ctx = avctx->priv_data; unsigned scaled_width, scaled_height; int16_t *ptr, *tmp; int i, j, k; scaled_width = width >> NB_LEVELS; scaled_height = height >> NB_LEVELS; tmp = ctx->filter[0]; for (i = 0; i < NB_LEVELS; i++) { int64_t scale_v = scaling_v[i]; int64_t scale_h = scaling_h[i]; scaled_width <<= 1; scaled_height <<= 1; ptr = dest; for (j = 0; j < scaled_height; j++) { filterfn(ptr, ctx->filter[1], scaled_width, scale_v); ptr += stride; } for (j = 0; j < scaled_width; j++) { ptr = dest + j; for (k = 0; k < scaled_height; k++) { tmp[k] = *ptr; ptr += stride; } filterfn(tmp, ctx->filter[1], scaled_height, scale_h); ptr = dest + j; for (k = 0; k < scaled_height; k++) { *ptr = tmp[k]; ptr += stride; } } } } static void build_luma_lut(AVCodecContext *avctx, int depth) { PixletContext *ctx = avctx->priv_data; int max = (1 << depth) - 1; if (ctx->depth == depth) return; ctx->depth = depth; for (int i = 0; i < FF_ARRAY_ELEMS(ctx->lut); i++) ctx->lut[i] = ((int64_t)i * i * 65535LL) / max / max; } static void postprocess_luma(AVCodecContext *avctx, AVFrame *frame, int w, int h, int depth) { PixletContext *ctx = avctx->priv_data; uint16_t *dsty = (uint16_t *)frame->data[0]; int16_t *srcy = (int16_t *)frame->data[0]; ptrdiff_t stridey = frame->linesize[0] / 2; uint16_t *lut = ctx->lut; int i, j; for (j = 0; j < h; j++) { for (i = 0; i < w; i++) { if (srcy[i] <= 0) dsty[i] = 0; else if (srcy[i] > ((1 << depth) - 1)) dsty[i] = 65535; else dsty[i] = lut[srcy[i]]; } dsty += stridey; srcy += stridey; } } static void postprocess_chroma(AVFrame *frame, int w, int h, int depth) { uint16_t *dstu = (uint16_t *)frame->data[1]; uint16_t *dstv = (uint16_t *)frame->data[2]; int16_t *srcu = (int16_t *)frame->data[1]; int16_t *srcv = (int16_t *)frame->data[2]; ptrdiff_t strideu = frame->linesize[1] / 2; ptrdiff_t stridev = frame->linesize[2] / 2; const unsigned add = 1 << (depth - 1); const unsigned shift = 16 - depth; int i, j; for (j = 0; j < h; j++) { for (i = 0; i < w; i++) { dstu[i] = av_clip_uintp2_c(add + srcu[i], depth) << shift; dstv[i] = av_clip_uintp2_c(add + srcv[i], depth) << shift; } dstu += strideu; dstv += stridev; srcu += strideu; srcv += stridev; } } static int decode_plane(AVCodecContext *avctx, int plane, const AVPacket *avpkt, AVFrame *frame) { PixletContext *ctx = avctx->priv_data; ptrdiff_t stride = frame->linesize[plane] / 2; unsigned shift = plane > 0; int16_t *dst; int i, ret; for (i = ctx->levels - 1; i >= 0; i--) { int32_t h = sign_extend(bytestream2_get_be32(&ctx->gb), 32); int32_t v = sign_extend(bytestream2_get_be32(&ctx->gb), 32); if (!h || !v) return AVERROR_INVALIDDATA; ctx->scaling[plane][H][i] = (1000000ULL << 32) / h; ctx->scaling[plane][V][i] = (1000000ULL << 32) / v; } bytestream2_skip(&ctx->gb, 4); dst = (int16_t *)frame->data[plane]; dst[0] = sign_extend(bytestream2_get_be16(&ctx->gb), 16); ret = init_get_bits8(&ctx->bc, avpkt->data + bytestream2_tell(&ctx->gb), bytestream2_get_bytes_left(&ctx->gb)); if (ret < 0) return ret; ret = read_low_coeffs(avctx, dst + 1, ctx->band[plane][0].width - 1, ctx->band[plane][0].width - 1, 0); if (ret < 0) { av_log(avctx, AV_LOG_ERROR, "error in lowpass coefficients for plane %d, top row\n", plane); return ret; } ret = read_low_coeffs(avctx, dst + stride, ctx->band[plane][0].height - 1, 1, stride); if (ret < 0) { av_log(avctx, AV_LOG_ERROR, "error in lowpass coefficients for plane %d, left column\n", plane); return ret; } ret = read_low_coeffs(avctx, dst + stride + 1, (ctx->band[plane][0].width - 1) * (ctx->band[plane][0].height - 1), ctx->band[plane][0].width - 1, stride); if (ret < 0) { av_log(avctx, AV_LOG_ERROR, "error in lowpass coefficients for plane %d, rest\n", plane); return ret; } bytestream2_skip(&ctx->gb, ret); if (bytestream2_get_bytes_left(&ctx->gb) <= 0) { av_log(avctx, AV_LOG_ERROR, "no bytes left\n"); return AVERROR_INVALIDDATA; } ret = read_highpass(avctx, avpkt->data, plane, frame); if (ret < 0) return ret; lowpass_prediction(dst, ctx->prediction, ctx->band[plane][0].width, ctx->band[plane][0].height, stride); reconstruction(avctx, (int16_t *)frame->data[plane], ctx->w >> shift, ctx->h >> shift, stride, ctx->scaling[plane][H], ctx->scaling[plane][V]); return 0; } static int pixlet_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt) { PixletContext *ctx = avctx->priv_data; int i, w, h, width, height, ret, version; AVFrame *p = data; ThreadFrame frame = { .f = data }; uint32_t pktsize, depth; bytestream2_init(&ctx->gb, avpkt->data, avpkt->size); pktsize = bytestream2_get_be32(&ctx->gb); if (pktsize <= 44 || pktsize - 4 > bytestream2_get_bytes_left(&ctx->gb)) { av_log(avctx, AV_LOG_ERROR, "Invalid packet size %"PRIu32"\n", pktsize); return AVERROR_INVALIDDATA; } version = bytestream2_get_le32(&ctx->gb); if (version != 1) avpriv_request_sample(avctx, "Version %d", version); bytestream2_skip(&ctx->gb, 4); if (bytestream2_get_be32(&ctx->gb) != 1) return AVERROR_INVALIDDATA; bytestream2_skip(&ctx->gb, 4); width = bytestream2_get_be32(&ctx->gb); height = bytestream2_get_be32(&ctx->gb); if ( width > INT_MAX - (1U << (NB_LEVELS + 1)) || height > INT_MAX - (1U << (NB_LEVELS + 1))) return AVERROR_INVALIDDATA; w = FFALIGN(width, 1 << (NB_LEVELS + 1)); h = FFALIGN(height, 1 << (NB_LEVELS + 1)); ctx->levels = bytestream2_get_be32(&ctx->gb); if (ctx->levels != NB_LEVELS) return AVERROR_INVALIDDATA; depth = bytestream2_get_be32(&ctx->gb); if (depth < 8 || depth > 15) { avpriv_request_sample(avctx, "Depth %d", depth); return AVERROR_INVALIDDATA; } build_luma_lut(avctx, depth); ret = ff_set_dimensions(avctx, w, h); if (ret < 0) return ret; avctx->width = width; avctx->height = height; if (ctx->w != w || ctx->h != h) { free_buffers(avctx); ctx->w = w; ctx->h = h; ret = init_decoder(avctx); if (ret < 0) { free_buffers(avctx); ctx->w = 0; ctx->h = 0; return ret; } } bytestream2_skip(&ctx->gb, 8); p->pict_type = AV_PICTURE_TYPE_I; p->key_frame = 1; p->color_range = AVCOL_RANGE_JPEG; ret = ff_thread_get_buffer(avctx, &frame, 0); if (ret < 0) return ret; for (i = 0; i < 3; i++) { ret = decode_plane(avctx, i, avpkt, frame.f); if (ret < 0) return ret; if (avctx->flags & AV_CODEC_FLAG_GRAY) break; } postprocess_luma(avctx, frame.f, ctx->w, ctx->h, ctx->depth); postprocess_chroma(frame.f, ctx->w >> 1, ctx->h >> 1, ctx->depth); *got_frame = 1; return pktsize; } const AVCodec ff_pixlet_decoder = { .name = "pixlet", .long_name = NULL_IF_CONFIG_SMALL("Apple Pixlet"), .type = AVMEDIA_TYPE_VIDEO, .id = AV_CODEC_ID_PIXLET, .init = pixlet_init, .close = pixlet_close, .decode = pixlet_decode_frame, .priv_data_size = sizeof(PixletContext), .capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS, .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP, };