/*

  * 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 "bytestream.h"

 #include "get_bits.h"
 #include "golomb.h"

 #include "h264.h"

 #include "h264dec.h"

 #include "h264_parse.h"

 #include "h264_ps.h"

 
 int ff_h264_pred_weight_table(GetBitContext *gb, const SPS *sps,
                               const int *ref_count, int slice_type_nos,

                               H264PredWeightTable *pwt,
                               int picture_structure, void *logctx)

 {

     int list, i, j;

     int luma_def, chroma_def;
 
     pwt->use_weight             = 0;
     pwt->use_weight_chroma      = 0;

     pwt->luma_log2_weight_denom = get_ue_golomb(gb);

     if (pwt->luma_log2_weight_denom > 7U) {

         av_log(logctx, AV_LOG_ERROR, "luma_log2_weight_denom %d is out of range\n", pwt->luma_log2_weight_denom);

         pwt->luma_log2_weight_denom = 0;
     }

     luma_def = 1 << pwt->luma_log2_weight_denom;

     if (sps->chroma_format_idc) {
         pwt->chroma_log2_weight_denom = get_ue_golomb(gb);
         if (pwt->chroma_log2_weight_denom > 7U) {
             av_log(logctx, AV_LOG_ERROR, "chroma_log2_weight_denom %d is out of range\n", pwt->chroma_log2_weight_denom);
             pwt->chroma_log2_weight_denom = 0;
         }
         chroma_def = 1 << pwt->chroma_log2_weight_denom;
     }

 
     for (list = 0; list < 2; list++) {
         pwt->luma_weight_flag[list]   = 0;
         pwt->chroma_weight_flag[list] = 0;
         for (i = 0; i < ref_count[list]; i++) {
             int luma_weight_flag, chroma_weight_flag;
 
             luma_weight_flag = get_bits1(gb);
             if (luma_weight_flag) {
                 pwt->luma_weight[i][list][0] = get_se_golomb(gb);
                 pwt->luma_weight[i][list][1] = get_se_golomb(gb);

                 if ((int8_t)pwt->luma_weight[i][list][0] != pwt->luma_weight[i][list][0] ||
                     (int8_t)pwt->luma_weight[i][list][1] != pwt->luma_weight[i][list][1])
                     goto out_range_weight;

                 if (pwt->luma_weight[i][list][0] != luma_def ||
                     pwt->luma_weight[i][list][1] != 0) {
                     pwt->use_weight             = 1;
                     pwt->luma_weight_flag[list] = 1;
                 }
             } else {
                 pwt->luma_weight[i][list][0] = luma_def;
                 pwt->luma_weight[i][list][1] = 0;
             }
 
             if (sps->chroma_format_idc) {
                 chroma_weight_flag = get_bits1(gb);
                 if (chroma_weight_flag) {
                     int j;
                     for (j = 0; j < 2; j++) {
                         pwt->chroma_weight[i][list][j][0] = get_se_golomb(gb);
                         pwt->chroma_weight[i][list][j][1] = get_se_golomb(gb);

                         if ((int8_t)pwt->chroma_weight[i][list][j][0] != pwt->chroma_weight[i][list][j][0] ||
                             (int8_t)pwt->chroma_weight[i][list][j][1] != pwt->chroma_weight[i][list][j][1])
                             goto out_range_weight;

                         if (pwt->chroma_weight[i][list][j][0] != chroma_def ||
                             pwt->chroma_weight[i][list][j][1] != 0) {
                             pwt->use_weight_chroma        = 1;
                             pwt->chroma_weight_flag[list] = 1;
                         }
                     }
                 } else {
                     int j;
                     for (j = 0; j < 2; j++) {
                         pwt->chroma_weight[i][list][j][0] = chroma_def;
                         pwt->chroma_weight[i][list][j][1] = 0;
                     }
                 }
             }

 
             // for MBAFF

             if (picture_structure == PICT_FRAME) {
                 pwt->luma_weight[16 + 2 * i][list][0] = pwt->luma_weight[16 + 2 * i + 1][list][0] = pwt->luma_weight[i][list][0];
                 pwt->luma_weight[16 + 2 * i][list][1] = pwt->luma_weight[16 + 2 * i + 1][list][1] = pwt->luma_weight[i][list][1];

                 if (sps->chroma_format_idc) {
                     for (j = 0; j < 2; j++) {
                         pwt->chroma_weight[16 + 2 * i][list][j][0] = pwt->chroma_weight[16 + 2 * i + 1][list][j][0] = pwt->chroma_weight[i][list][j][0];
                         pwt->chroma_weight[16 + 2 * i][list][j][1] = pwt->chroma_weight[16 + 2 * i + 1][list][j][1] = pwt->chroma_weight[i][list][j][1];
                     }

                 }

             }

         }
         if (slice_type_nos != AV_PICTURE_TYPE_B)
             break;
     }
     pwt->use_weight = pwt->use_weight || pwt->use_weight_chroma;
     return 0;

 out_range_weight:
     avpriv_request_sample(logctx, "Out of range weight\n");
     return AVERROR_INVALIDDATA;

 }

 
 /**
  * Check if the top & left blocks are available if needed and
  * change the dc mode so it only uses the available blocks.
  */
 int ff_h264_check_intra4x4_pred_mode(int8_t *pred_mode_cache, void *logctx,
                                      int top_samples_available, int left_samples_available)
 {
     static const int8_t top[12] = {
         -1, 0, LEFT_DC_PRED, -1, -1, -1, -1, -1, 0
     };
     static const int8_t left[12] = {
         0, -1, TOP_DC_PRED, 0, -1, -1, -1, 0, -1, DC_128_PRED
     };
     int i;
 
     if (!(top_samples_available & 0x8000)) {
         for (i = 0; i < 4; i++) {
             int status = top[pred_mode_cache[scan8[0] + i]];
             if (status < 0) {
                 av_log(logctx, AV_LOG_ERROR,

                        "top block unavailable for requested intra mode %d\n",

                        status);
                 return AVERROR_INVALIDDATA;
             } else if (status) {
                 pred_mode_cache[scan8[0] + i] = status;
             }
         }
     }
 
     if ((left_samples_available & 0x8888) != 0x8888) {
         static const int mask[4] = { 0x8000, 0x2000, 0x80, 0x20 };
         for (i = 0; i < 4; i++)
             if (!(left_samples_available & mask[i])) {
                 int status = left[pred_mode_cache[scan8[0] + 8 * i]];
                 if (status < 0) {
                     av_log(logctx, AV_LOG_ERROR,
                            "left block unavailable for requested intra4x4 mode %d\n",
                            status);
                     return AVERROR_INVALIDDATA;
                 } else if (status) {
                     pred_mode_cache[scan8[0] + 8 * i] = status;
                 }
             }
     }
 
     return 0;
 }
 
 /**
  * Check if the top & left blocks are available if needed and
  * change the dc mode so it only uses the available blocks.
  */
 int ff_h264_check_intra_pred_mode(void *logctx, int top_samples_available,
                                   int left_samples_available,
                                   int mode, int is_chroma)
 {
     static const int8_t top[4]  = { LEFT_DC_PRED8x8, 1, -1, -1 };
     static const int8_t left[5] = { TOP_DC_PRED8x8, -1,  2, -1, DC_128_PRED8x8 };
 
     if (mode > 3U) {
         av_log(logctx, AV_LOG_ERROR,
                "out of range intra chroma pred mode\n");
         return AVERROR_INVALIDDATA;
     }
 
     if (!(top_samples_available & 0x8000)) {
         mode = top[mode];
         if (mode < 0) {
             av_log(logctx, AV_LOG_ERROR,
                    "top block unavailable for requested intra mode\n");
             return AVERROR_INVALIDDATA;
         }
     }
 
     if ((left_samples_available & 0x8080) != 0x8080) {
         mode = left[mode];

         if (mode < 0) {
             av_log(logctx, AV_LOG_ERROR,
                    "left block unavailable for requested intra mode\n");
             return AVERROR_INVALIDDATA;
         }

         if (is_chroma && (left_samples_available & 0x8080)) {
             // mad cow disease mode, aka MBAFF + constrained_intra_pred
             mode = ALZHEIMER_DC_L0T_PRED8x8 +
                    (!(left_samples_available & 0x8000)) +
                    2 * (mode == DC_128_PRED8x8);
         }
     }
 
     return mode;
 }

 
 int ff_h264_parse_ref_count(int *plist_count, int ref_count[2],
                             GetBitContext *gb, const PPS *pps,

                             int slice_type_nos, int picture_structure, void *logctx)

 {
     int list_count;

     int num_ref_idx_active_override_flag;

 
     // set defaults, might be overridden a few lines later
     ref_count[0] = pps->ref_count[0];
     ref_count[1] = pps->ref_count[1];
 
     if (slice_type_nos != AV_PICTURE_TYPE_I) {

         unsigned max[2];
         max[0] = max[1] = picture_structure == PICT_FRAME ? 15 : 31;
 

         num_ref_idx_active_override_flag = get_bits1(gb);
 
         if (num_ref_idx_active_override_flag) {
             ref_count[0] = get_ue_golomb(gb) + 1;
             if (slice_type_nos == AV_PICTURE_TYPE_B) {
                 ref_count[1] = get_ue_golomb(gb) + 1;

             } else
                 // full range is spec-ok in this case, even for frames
                 ref_count[1] = 1;
         }
 
         if (ref_count[0] - 1 > max[0] || ref_count[1] - 1 > max[1]) {
             av_log(logctx, AV_LOG_ERROR, "reference overflow %u > %u or %u > %u\n",
                    ref_count[0] - 1, max[0], ref_count[1] - 1, max[1]);
             ref_count[0] = ref_count[1] = 0;
             *plist_count = 0;

             goto fail;

         }
 
         if (slice_type_nos == AV_PICTURE_TYPE_B)
             list_count = 2;
         else
             list_count = 1;
     } else {
         list_count   = 0;
         ref_count[0] = ref_count[1] = 0;
     }
 
     *plist_count = list_count;
 
     return 0;

 fail:
     *plist_count = 0;
     ref_count[0] = 0;
     ref_count[1] = 0;
     return AVERROR_INVALIDDATA;

 }

 
 int ff_h264_init_poc(int pic_field_poc[2], int *pic_poc,
                      const SPS *sps, H264POCContext *pc,
                      int picture_structure, int nal_ref_idc)
 {
     const int max_frame_num = 1 << sps->log2_max_frame_num;
     int field_poc[2];
 
     pc->frame_num_offset = pc->prev_frame_num_offset;
     if (pc->frame_num < pc->prev_frame_num)
         pc->frame_num_offset += max_frame_num;
 
     if (sps->poc_type == 0) {
         const int max_poc_lsb = 1 << sps->log2_max_poc_lsb;
 
         if (pc->poc_lsb < pc->prev_poc_lsb &&
             pc->prev_poc_lsb - pc->poc_lsb >= max_poc_lsb / 2)
             pc->poc_msb = pc->prev_poc_msb + max_poc_lsb;
         else if (pc->poc_lsb > pc->prev_poc_lsb &&
                  pc->prev_poc_lsb - pc->poc_lsb < -max_poc_lsb / 2)
             pc->poc_msb = pc->prev_poc_msb - max_poc_lsb;
         else
             pc->poc_msb = pc->prev_poc_msb;
         field_poc[0] =
         field_poc[1] = pc->poc_msb + pc->poc_lsb;
         if (picture_structure == PICT_FRAME)
             field_poc[1] += pc->delta_poc_bottom;
     } else if (sps->poc_type == 1) {
         int abs_frame_num, expected_delta_per_poc_cycle, expectedpoc;
         int i;
 
         if (sps->poc_cycle_length != 0)
             abs_frame_num = pc->frame_num_offset + pc->frame_num;
         else
             abs_frame_num = 0;
 
         if (nal_ref_idc == 0 && abs_frame_num > 0)
             abs_frame_num--;
 
         expected_delta_per_poc_cycle = 0;
         for (i = 0; i < sps->poc_cycle_length; i++)
             // FIXME integrate during sps parse
             expected_delta_per_poc_cycle += sps->offset_for_ref_frame[i];
 
         if (abs_frame_num > 0) {
             int poc_cycle_cnt          = (abs_frame_num - 1) / sps->poc_cycle_length;
             int frame_num_in_poc_cycle = (abs_frame_num - 1) % sps->poc_cycle_length;
 
             expectedpoc = poc_cycle_cnt * expected_delta_per_poc_cycle;
             for (i = 0; i <= frame_num_in_poc_cycle; i++)
                 expectedpoc = expectedpoc + sps->offset_for_ref_frame[i];
         } else
             expectedpoc = 0;
 
         if (nal_ref_idc == 0)
             expectedpoc = expectedpoc + sps->offset_for_non_ref_pic;
 
         field_poc[0] = expectedpoc + pc->delta_poc[0];
         field_poc[1] = field_poc[0] + sps->offset_for_top_to_bottom_field;
 
         if (picture_structure == PICT_FRAME)
             field_poc[1] += pc->delta_poc[1];
     } else {
         int poc = 2 * (pc->frame_num_offset + pc->frame_num);
 
         if (!nal_ref_idc)
             poc--;
 
         field_poc[0] = poc;
         field_poc[1] = poc;
     }
 
     if (picture_structure != PICT_BOTTOM_FIELD)
         pic_field_poc[0] = field_poc[0];
     if (picture_structure != PICT_TOP_FIELD)
         pic_field_poc[1] = field_poc[1];
     *pic_poc = FFMIN(pic_field_poc[0], pic_field_poc[1]);
 
     return 0;
 }

 
 static int decode_extradata_ps(const uint8_t *data, int size, H264ParamSets *ps,
                                int is_avc, void *logctx)
 {
     H2645Packet pkt = { 0 };
     int i, ret = 0;
 

     ret = ff_h2645_packet_split(&pkt, data, size, logctx, is_avc, 2, AV_CODEC_ID_H264, 1);

     if (ret < 0) {
         ret = 0;

         goto fail;

     }

 
     for (i = 0; i < pkt.nb_nals; i++) {
         H2645NAL *nal = &pkt.nals[i];
         switch (nal->type) {

         case H264_NAL_SPS:

             ret = ff_h264_decode_seq_parameter_set(&nal->gb, logctx, ps, 0);

             if (ret < 0)
                 goto fail;
             break;

         case H264_NAL_PPS:

             ret = ff_h264_decode_picture_parameter_set(&nal->gb, logctx, ps,
                                                        nal->size_bits);
             if (ret < 0)
                 goto fail;
             break;
         default:
             av_log(logctx, AV_LOG_VERBOSE, "Ignoring NAL type %d in extradata\n",
                    nal->type);
             break;
         }
     }
 
 fail:
     ff_h2645_packet_uninit(&pkt);
     return ret;
 }
 
 /* There are (invalid) samples in the wild with mp4-style extradata, where the
  * parameter sets are stored unescaped (i.e. as RBSP).
  * This function catches the parameter set decoding failure and tries again
  * after escaping it */
 static int decode_extradata_ps_mp4(const uint8_t *buf, int buf_size, H264ParamSets *ps,
                                    int err_recognition, void *logctx)
 {
     int ret;
 
     ret = decode_extradata_ps(buf, buf_size, ps, 1, logctx);
     if (ret < 0 && !(err_recognition & AV_EF_EXPLODE)) {
         GetByteContext gbc;
         PutByteContext pbc;
         uint8_t *escaped_buf;
         int escaped_buf_size;
 
         av_log(logctx, AV_LOG_WARNING,
                "SPS decoding failure, trying again after escaping the NAL\n");
 
         if (buf_size / 2 >= (INT16_MAX - AV_INPUT_BUFFER_PADDING_SIZE) / 3)
             return AVERROR(ERANGE);
         escaped_buf_size = buf_size * 3 / 2 + AV_INPUT_BUFFER_PADDING_SIZE;
         escaped_buf = av_mallocz(escaped_buf_size);
         if (!escaped_buf)
             return AVERROR(ENOMEM);
 
         bytestream2_init(&gbc, buf, buf_size);
         bytestream2_init_writer(&pbc, escaped_buf, escaped_buf_size);
 
         while (bytestream2_get_bytes_left(&gbc)) {
             if (bytestream2_get_bytes_left(&gbc) >= 3 &&
                 bytestream2_peek_be24(&gbc) <= 3) {
                 bytestream2_put_be24(&pbc, 3);
                 bytestream2_skip(&gbc, 2);
             } else
                 bytestream2_put_byte(&pbc, bytestream2_get_byte(&gbc));
         }
 
         escaped_buf_size = bytestream2_tell_p(&pbc);
         AV_WB16(escaped_buf, escaped_buf_size - 2);
 
         ret = decode_extradata_ps(escaped_buf, escaped_buf_size, ps, 1, logctx);
         av_freep(&escaped_buf);
         if (ret < 0)
             return ret;
     }
 
     return 0;
 }
 
 int ff_h264_decode_extradata(const uint8_t *data, int size, H264ParamSets *ps,
                              int *is_avc, int *nal_length_size,
                              int err_recognition, void *logctx)
 {
     int ret;
 

     if (!data || size <= 0)
         return -1;
 

     if (data[0] == 1) {
         int i, cnt, nalsize;
         const uint8_t *p = data;
 
         *is_avc = 1;
 
         if (size < 7) {
             av_log(logctx, AV_LOG_ERROR, "avcC %d too short\n", size);
             return AVERROR_INVALIDDATA;
         }
 
         // Decode sps from avcC
         cnt = *(p + 5) & 0x1f; // Number of sps
         p  += 6;
         for (i = 0; i < cnt; i++) {
             nalsize = AV_RB16(p) + 2;

             if (nalsize > size - (p - data))

                 return AVERROR_INVALIDDATA;
             ret = decode_extradata_ps_mp4(p, nalsize, ps, err_recognition, logctx);
             if (ret < 0) {
                 av_log(logctx, AV_LOG_ERROR,
                        "Decoding sps %d from avcC failed\n", i);
                 return ret;
             }
             p += nalsize;
         }
         // Decode pps from avcC
         cnt = *(p++); // Number of pps
         for (i = 0; i < cnt; i++) {
             nalsize = AV_RB16(p) + 2;

             if (nalsize > size - (p - data))

                 return AVERROR_INVALIDDATA;
             ret = decode_extradata_ps_mp4(p, nalsize, ps, err_recognition, logctx);
             if (ret < 0) {
                 av_log(logctx, AV_LOG_ERROR,
                        "Decoding pps %d from avcC failed\n", i);
                 return ret;
             }
             p += nalsize;
         }
         // Store right nal length size that will be used to parse all other nals
         *nal_length_size = (data[4] & 0x03) + 1;
     } else {
         *is_avc = 0;
         ret = decode_extradata_ps(data, size, ps, 0, logctx);
         if (ret < 0)
             return ret;
     }

     return size;

 }

 
 /**
  * Compute profile from profile_idc and constraint_set?_flags.
  *
  * @param sps SPS
  *
  * @return profile as defined by FF_PROFILE_H264_*
  */
 int ff_h264_get_profile(const SPS *sps)
 {
     int profile = sps->profile_idc;
 
     switch (sps->profile_idc) {
     case FF_PROFILE_H264_BASELINE:
         // constraint_set1_flag set to 1
         profile |= (sps->constraint_set_flags & 1 << 1) ? FF_PROFILE_H264_CONSTRAINED : 0;
         break;
     case FF_PROFILE_H264_HIGH_10:
     case FF_PROFILE_H264_HIGH_422:
     case FF_PROFILE_H264_HIGH_444_PREDICTIVE:
         // constraint_set3_flag set to 1
         profile |= (sps->constraint_set_flags & 1 << 3) ? FF_PROFILE_H264_INTRA : 0;
         break;
     }
 
     return profile;
 }