From 359747b110c8b111749eef95d2893bb617bd727e Mon Sep 17 00:00:00 2001 From: Michael Chaban Date: Thu, 19 Jul 2018 00:38:31 +0300 Subject: [PATCH 2/3] libavcodec/escape130: the default YUV colorspace replaced by original decoder RGB colorspace The default ffmpeg colorspace is totally wrong for escape130. It must be the same as original decoder has. Also, the frame header analysis is added. --- libavcodec/escape130.c | 102 ++++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 84 insertions(+), 18 deletions(-) diff --git a/libavcodec/escape130.c b/libavcodec/escape130.c index c1a976b920..f1c965a116 100644 --- a/libavcodec/escape130.c +++ b/libavcodec/escape130.c @@ -1,6 +1,7 @@ /* * Escape 130 video decoder * Copyright (C) 2008 Eli Friedman (eli.friedman gmail.com) + * Copyright (C) 2018 Michael Chaban (arsunt gmail.com) * * This file is part of FFmpeg. * @@ -38,6 +39,11 @@ typedef struct Escape130Context { int linesize[3]; } Escape130Context; +// Header flags definition +#define MASK_VERSION 0x0000FFFF // must be 0x0130 for Escape130 +#define MASK_NONLINEAR 0x00010000 // non-linear chroma code flag +#define MASK_KEYFRAME 0x80000000 // the keyframe flag + static const uint8_t offset_table[] = { 2, 4, 10, 20 }; static const int8_t sign_table[64][4] = { { 0, 0, 0, 0 }, @@ -113,10 +119,41 @@ static const uint8_t chroma_vals[] = { 172, 180, 188, 196, 204, 212, 220, 228 }; +static int16_t cb2rgb[2][32][3]; +static int16_t cr2rgb[2][32][3]; + +/* + * Escape130 colorspace based on T-REC-T.871 formulas + * R = Y + 1.402 * V; + * G = G = Y - (0.114 * 1.772 * U + 0.299 * 1.402 * V) / 0.587; + * B = Y + 1.772 * U; + */ +static void generate_chroma2rgb(void) +{ + int i, mode, chroma; + + // Perform calculation for both chroma tables: linear and non-linear. + // Linear table has wider range and it produces more contrast colors, + // but non-linear one is more accurate + for (mode = 0; mode < 2; ++mode) { + for (i = 0; i < 32; ++i) { + chroma = (mode ? chroma_vals[i] : (i << 3)) - 128; + + cb2rgb[mode][i][0] = 0; + cb2rgb[mode][i][1] = (1000500 * 587 - 114 * 1772 * chroma) / 1000 / 587 - 1000; + cb2rgb[mode][i][2] = (1000500 + 1772 * chroma) / 1000 - 1000; + + cr2rgb[mode][i][0] = (1000500 + 1402 * chroma) / 1000 - 1000; + cr2rgb[mode][i][1] = (1000500 * 587 - 299 * 1402 * chroma) / 1000 / 587 - 1000; + cr2rgb[mode][i][2] = 0; + } + } +} + static av_cold int escape130_decode_init(AVCodecContext *avctx) { Escape130Context *s = avctx->priv_data; - avctx->pix_fmt = AV_PIX_FMT_YUV420P; + avctx->pix_fmt = AV_PIX_FMT_RGB24; if ((avctx->width & 1) || (avctx->height & 1)) { av_log(avctx, AV_LOG_ERROR, @@ -149,6 +186,8 @@ static av_cold int escape130_decode_init(AVCodecContext *avctx) memset(s->old_u, 0x10, avctx->width * avctx->height / 4); memset(s->old_v, 0x10, avctx->width * avctx->height / 4); + generate_chroma2rgb(); + return 0; } @@ -196,20 +235,21 @@ static int escape130_decode_frame(AVCodecContext *avctx, void *data, Escape130Context *s = avctx->priv_data; AVFrame *pic = data; GetBitContext gb; + unsigned frame_flags, frame_size; int ret; uint8_t *old_y, *old_cb, *old_cr, *new_y, *new_cb, *new_cr; - uint8_t *dstY, *dstU, *dstV; + uint8_t *dst_line, *dst_rgb; unsigned old_y_stride, old_cb_stride, old_cr_stride, new_y_stride, new_cb_stride, new_cr_stride; unsigned total_blocks = avctx->width * avctx->height / 4, block_index, block_x = 0; unsigned y[4] = { 0 }, cb = 0x10, cr = 0x10; - int skip = -1, y_avg = 0, i, j; + int skip = -1, chroma_mode = 0, y_avg = 0, r, g, b, i, j, m, n; uint8_t *ya = s->old_y_avg; - // first 16 bytes are header; no useful information in here + // first 16 bytes are header if (buf_size <= 16) { av_log(avctx, AV_LOG_ERROR, "Insufficient frame data\n"); return AVERROR_INVALIDDATA; @@ -220,7 +260,23 @@ static int escape130_decode_frame(AVCodecContext *avctx, void *data, if ((ret = init_get_bits8(&gb, avpkt->data, avpkt->size)) < 0) return ret; - skip_bits_long(&gb, 16 * 8); + + frame_flags = get_bits_long(&gb, 32); + if ((frame_flags & MASK_VERSION) != 0x0130) { + av_log(avctx, AV_LOG_ERROR, "Invalid frame header\n"); + return AVERROR_INVALIDDATA; + } + + frame_size = get_bits_long(&gb, 32); + if (buf_size < frame_size) { + av_log(avctx, AV_LOG_ERROR, "Insufficient frame data\n"); + return AVERROR_INVALIDDATA; + } + + // the following 8 bytes were reserved and never used (filled with zeros) + skip_bits_long(&gb, 64); + + chroma_mode = (frame_flags & MASK_NONLINEAR) ? 1 : 0; new_y = s->new_y; new_cb = s->new_u; @@ -318,22 +374,32 @@ static int escape130_decode_frame(AVCodecContext *avctx, void *data, new_y = s->new_y; new_cb = s->new_u; new_cr = s->new_v; - dstY = pic->data[0]; - dstU = pic->data[1]; - dstV = pic->data[2]; - for (j = 0; j < avctx->height; j++) { - for (i = 0; i < avctx->width; i++) - dstY[i] = new_y[i] << 2; - dstY += pic->linesize[0]; - new_y += new_y_stride; - } + dst_line = pic->data[0]; + for (j = 0; j < avctx->height / 2; j++) { for (i = 0; i < avctx->width / 2; i++) { - dstU[i] = chroma_vals[new_cb[i]]; - dstV[i] = chroma_vals[new_cr[i]]; + for (m = 0; m < 2; m++) { + for (n = 0; n < 2; n++) { + r = (new_y[i * 2 + m * new_y_stride + n] << 2) + + cb2rgb[chroma_mode][new_cb[i]][0] + + cr2rgb[chroma_mode][new_cr[i]][0]; + g = (new_y[i * 2 + m * new_y_stride + n] << 2) + + cb2rgb[chroma_mode][new_cb[i]][1] + + cr2rgb[chroma_mode][new_cr[i]][1]; + b = (new_y[i * 2 + m * new_y_stride + n] << 2) + + cb2rgb[chroma_mode][new_cb[i]][2] + + cr2rgb[chroma_mode][new_cr[i]][2]; + + dst_rgb = dst_line + i * 6 + m * pic->linesize[0] + n * 3; + + dst_rgb[0] = av_clip(r, 0, 255); + dst_rgb[1] = av_clip(g, 0, 255); + dst_rgb[2] = av_clip(b, 0, 255); + } + } } - dstU += pic->linesize[1]; - dstV += pic->linesize[2]; + dst_line += pic->linesize[0] * 2; + new_y += new_y_stride * 2; new_cb += new_cb_stride; new_cr += new_cr_stride; } -- 2.16.1.windows.4