Add a function to parse Dirac's sequence header

Originally committed as revision 21127 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/dirac.c

+/*
+ * Copyright (C) 2007 Marco Gerards <marco@gnu.org>
+ * Copyright (C) 2009 David Conrad
+ *
+ * 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
+ */
+
+/**
+ * @file libavcodec/dirac.c
+ * Dirac Decoder
+ * @author Marco Gerards <marco@gnu.org>
+ */
+
+#include "dirac.h"
+#include "avcodec.h"
+#include "golomb.h"
+#include "mpeg12data.h"
+
+// defaults for source parameters
+static const dirac_source_params dirac_source_parameters_defaults[] = {
+    { 640,  480,  2, 0, 0, 1,  1, 640,  480,  0, 0, 1, 0 },
+    { 176,  120,  2, 0, 0, 9,  2, 176,  120,  0, 0, 1, 1 },
+    { 176,  144,  2, 0, 1, 10, 3, 176,  144,  0, 0, 1, 2 },
+    { 352,  240,  2, 0, 0, 9,  2, 352,  240,  0, 0, 1, 1 },
+    { 352,  288,  2, 0, 1, 10, 3, 352,  288,  0, 0, 1, 2 },
+    { 704,  480,  2, 0, 0, 9,  2, 704,  480,  0, 0, 1, 1 },
+    { 704,  576,  2, 0, 1, 10, 3, 704,  576,  0, 0, 1, 2 },
+    { 720,  480,  1, 1, 0, 4,  2, 704,  480,  8, 0, 3, 1 },
+    { 720,  576,  1, 1, 1, 3,  3, 704,  576,  8, 0, 3, 2 },
+
+    { 1280, 720,  1, 0, 1, 7,  1, 1280, 720,  0, 0, 3, 3 },
+    { 1280, 720,  1, 0, 1, 6,  1, 1280, 720,  0, 0, 3, 3 },
+    { 1920, 1080, 1, 1, 1, 4,  1, 1920, 1080, 0, 0, 3, 3 },
+    { 1920, 1080, 1, 1, 1, 3,  1, 1920, 1080, 0, 0, 3, 3 },
+    { 1920, 1080, 1, 0, 1, 7,  1, 1920, 1080, 0, 0, 3, 3 },
+    { 1920, 1080, 1, 0, 1, 6,  1, 1920, 1080, 0, 0, 3, 3 },
+    { 2048, 1080, 0, 0, 1, 2,  1, 2048, 1080, 0, 0, 4, 4 },
+    { 4096, 2160, 0, 0, 1, 2,  1, 4096, 2160, 0, 0, 4, 4 },
+
+    { 3840, 2160, 1, 0, 1, 7,  1, 3840, 2160, 0, 0, 3, 3 },
+    { 3840, 2160, 1, 0, 1, 6,  1, 3840, 2160, 0, 0, 3, 3 },
+    { 7680, 4320, 1, 0, 1, 7,  1, 3840, 2160, 0, 0, 3, 3 },
+    { 7680, 4320, 1, 0, 1, 6,  1, 3840, 2160, 0, 0, 3, 3 },
+};
+
+static const AVRational dirac_preset_aspect_ratios[] = {
+    {1, 1},
+    {10, 11},
+    {12, 11},
+    {40, 33},
+    {16, 11},
+    {4, 3},
+};
+
+static const AVRational dirac_frame_rate[] = {
+    {15000, 1001},
+    {25, 2},
+};
+
+static const struct {
+    uint8_t             bitdepth;
+    enum AVColorRange   color_range;
+} pixel_range_presets[] = {
+    {8,  AVCOL_RANGE_JPEG},
+    {8,  AVCOL_RANGE_MPEG},
+    {10, AVCOL_RANGE_MPEG},
+    {12, AVCOL_RANGE_MPEG},
+};
+
+static const enum AVColorPrimaries dirac_primaries[] = {
+    AVCOL_PRI_BT709,
+    AVCOL_PRI_SMPTE170M,
+    AVCOL_PRI_BT470BG,
+};
+
+static const struct {
+    enum AVColorPrimaries color_primaries;
+    enum AVColorSpace colorspace;
+    enum AVColorTransferCharacteristic color_trc;
+} dirac_color_presets[] = {
+    { AVCOL_PRI_BT709,     AVCOL_SPC_BT709,   AVCOL_TRC_BT709 },
+    { AVCOL_PRI_SMPTE170M, AVCOL_SPC_BT470BG, AVCOL_TRC_BT709 },
+    { AVCOL_PRI_BT470BG,   AVCOL_SPC_BT470BG, AVCOL_TRC_BT709 },
+    { AVCOL_PRI_BT709,     AVCOL_SPC_BT709,   AVCOL_TRC_BT709 },
+    { AVCOL_PRI_BT709,     AVCOL_SPC_BT709,   AVCOL_TRC_UNSPECIFIED /* DCinema */ },
+};
+
+static const enum PixelFormat dirac_pix_fmt[2][3] = {
+    { PIX_FMT_YUV444P,  PIX_FMT_YUV422P,  PIX_FMT_YUV420P  },
+    { PIX_FMT_YUVJ444P, PIX_FMT_YUVJ422P, PIX_FMT_YUVJ420P },
+};
+
+static int parse_source_parameters(AVCodecContext *avctx, GetBitContext *gb,
+                                   dirac_source_params *source)
+{
+    AVRational frame_rate = (AVRational){0,0};
+    unsigned luma_depth = 8, luma_offset = 16;
+    int idx;
+
+    if (get_bits1(gb)) {
+        source->width  = svq3_get_ue_golomb(gb);
+        source->height = svq3_get_ue_golomb(gb);
+    }
+
+    // chroma subsampling
+    if (get_bits1(gb))
+        source->chroma_format = svq3_get_ue_golomb(gb);
+    if (source->chroma_format > 2) {
+        av_log(avctx, AV_LOG_ERROR, "Unknown chroma format %d\n",
+               source->chroma_format);
+        return -1;
+    }
+
+    if (get_bits1(gb))
+        source->interlaced = svq3_get_ue_golomb(gb);
+    if (source->interlaced > 1)
+        return -1;
+
+    // frame rate
+    if (get_bits1(gb)) {
+        source->frame_rate_index = svq3_get_ue_golomb(gb);
+
+        if (source->frame_rate_index > 10)
+            return -1;
+
+        if (!source->frame_rate_index) {
+            frame_rate.num = svq3_get_ue_golomb(gb);
+            frame_rate.den = svq3_get_ue_golomb(gb);
+        }
+    }
+    if (source->frame_rate_index > 0) {
+        if (source->frame_rate_index <= 8)
+            frame_rate = ff_frame_rate_tab[source->frame_rate_index];
+        else
+            frame_rate = dirac_frame_rate[source->frame_rate_index-9];
+    }
+    av_reduce(&avctx->time_base.num, &avctx->time_base.den,
+              frame_rate.den, frame_rate.num, 1<<30);
+
+    // aspect ratio
+    if (get_bits1(gb)) {
+        source->aspect_ratio_index = svq3_get_ue_golomb(gb);
+
+        if (source->aspect_ratio_index > 6)
+            return -1;
+
+        if (!source->aspect_ratio_index) {
+            avctx->sample_aspect_ratio.num = svq3_get_ue_golomb(gb);
+            avctx->sample_aspect_ratio.den = svq3_get_ue_golomb(gb);
+        }
+    }
+    if (source->aspect_ratio_index > 0)
+        avctx->sample_aspect_ratio =
+                dirac_preset_aspect_ratios[source->aspect_ratio_index-1];
+
+    if (get_bits1(gb)) {
+        source->clean_width        = svq3_get_ue_golomb(gb);
+        source->clean_height       = svq3_get_ue_golomb(gb);
+        source->clean_left_offset  = svq3_get_ue_golomb(gb);
+        source->clean_right_offset = svq3_get_ue_golomb(gb);
+    }
+
+    // Override signal range.
+    if (get_bits1(gb)) {
+        source->pixel_range_index = svq3_get_ue_golomb(gb);
+
+        if (source->pixel_range_index > 4)
+            return -1;
+
+        // This assumes either fullrange or MPEG levels only
+        if (!source->pixel_range_index) {
+            luma_offset = svq3_get_ue_golomb(gb);
+            luma_depth  = av_log2(svq3_get_ue_golomb(gb))+1;
+            svq3_get_ue_golomb(gb); // chroma offset
+            svq3_get_ue_golomb(gb); // chroma excursion
+
+            avctx->color_range = luma_offset ? AVCOL_RANGE_MPEG : AVCOL_RANGE_JPEG;
+        }
+    }
+    if (source->pixel_range_index > 0) {
+        idx                = source->pixel_range_index-1;
+        luma_depth         = pixel_range_presets[idx].bitdepth;
+        avctx->color_range = pixel_range_presets[idx].color_range;
+    }
+
+    if (luma_depth > 8)
+        av_log(avctx, AV_LOG_WARNING, "Bitdepth greater than 8");
+
+    avctx->pix_fmt = dirac_pix_fmt[!luma_offset][source->chroma_format];
+
+    // color spec
+    if (get_bits1(gb)) {
+        idx = source->color_spec_index = svq3_get_ue_golomb(gb);
+
+        if (source->color_spec_index > 4)
+            return -1;
+
+        avctx->color_primaries = dirac_color_presets[idx].color_primaries;
+        avctx->colorspace      = dirac_color_presets[idx].colorspace;
+        avctx->color_trc       = dirac_color_presets[idx].color_trc;
+
+        if (!source->color_spec_index) {
+            if (get_bits1(gb)) {
+                idx = svq3_get_ue_golomb(gb);
+                if (idx < 3)
+                    avctx->color_primaries = dirac_primaries[idx];
+            }
+
+            if (get_bits1(gb)) {
+                idx = svq3_get_ue_golomb(gb);
+                if (!idx)
+                    avctx->colorspace = AVCOL_SPC_BT709;
+                else if (idx == 1)
+                    avctx->colorspace = AVCOL_SPC_BT470BG;
+            }
+
+            if (get_bits1(gb) && !svq3_get_ue_golomb(gb))
+                avctx->color_trc = AVCOL_TRC_BT709;
+        }
+    } else {
+        idx = source->color_spec_index;
+        avctx->color_primaries = dirac_color_presets[idx].color_primaries;
+        avctx->colorspace      = dirac_color_presets[idx].colorspace;
+        avctx->color_trc       = dirac_color_presets[idx].color_trc;
+    }
+
+    return 0;
+}
+
+int ff_dirac_parse_sequence_header(AVCodecContext *avctx, GetBitContext *gb,
+                                   dirac_source_params *source)
+{
+    unsigned version_major, version_minor;
+    unsigned video_format, picture_coding_mode;
+
+    version_major  = svq3_get_ue_golomb(gb);
+    version_minor  = svq3_get_ue_golomb(gb);
+    avctx->profile = svq3_get_ue_golomb(gb);
+    avctx->level   = svq3_get_ue_golomb(gb);
+    video_format   = svq3_get_ue_golomb(gb);
+
+    if (version_major < 2)
+        av_log(avctx, AV_LOG_WARNING, "Stream is old and may not work\n");
+    else if (version_major > 2)
+        av_log(avctx, AV_LOG_WARNING, "Stream may have unhandled features\n");
+
+    if (video_format > 20)
+        return -1;
+
+    // Fill in defaults for the source parameters.
+    *source = dirac_source_parameters_defaults[video_format];
+
+    // Override the defaults.
+    if (parse_source_parameters(avctx, gb, source))
+        return -1;
+
+    if (avcodec_check_dimensions(avctx, source->width, source->height))
+        return -1;
+
+    avcodec_set_dimensions(avctx, source->width, source->height);
+
+    // currently only used to signal field coding
+    picture_coding_mode = svq3_get_ue_golomb(gb);
+    if (picture_coding_mode != 0) {
+        av_log(avctx, AV_LOG_ERROR, "Unsupported picture coding mode %d",
+               picture_coding_mode);
+        return -1;
+    }
+    return 0;
+}

libavcodec/dirac.h

+/*
+ * Copyright (C) 2007 Marco Gerards <marco@gnu.org>
+ * Copyright (C) 2009 David Conrad
+ *
+ * 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
+ */
+
+#ifndef AVCODEC_DIRAC_H
+#define AVCODEC_DIRAC_H
+
+/**
+ * @file libavcodec/dirac.h
+ * Interfaces to Dirac Decoder/Encoder
+ * @author Marco Gerards <marco@gnu.org>
+ */
+
+#include "avcodec.h"
+#include "get_bits.h"
+
+typedef struct {
+    unsigned width;
+    unsigned height;
+    uint8_t chroma_format;          ///< 0: 444  1: 422  2: 420
+
+    uint8_t interlaced;
+    uint8_t top_field_first;
+
+    uint8_t frame_rate_index;       ///< index into dirac_frame_rate[]
+    uint8_t aspect_ratio_index;     ///< index into dirac_aspect_ratio[]
+
+    uint16_t clean_width;
+    uint16_t clean_height;
+    uint16_t clean_left_offset;
+    uint16_t clean_right_offset;
+
+    uint8_t pixel_range_index;      ///< index into dirac_pixel_range_presets[]
+    uint8_t color_spec_index;       ///< index into dirac_color_spec_presets[]
+} dirac_source_params;
+
+int ff_dirac_parse_sequence_header(AVCodecContext *avctx, GetBitContext *gb,
+                                   dirac_source_params *source);
+
+#endif /* AVCODEC_DIRAC_H */