/* * AVS2-P2/IEEE1857.4 video parser. * Copyright (c) 2018  Huiwen Ren <hwrenx@gmail.com> * * 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 "libavutil/avutil.h"#include "avs2.h"#include "get_bits.h"#include "parser.h" static int avs2_find_frame_end(ParseContext *pc, const uint8_t *buf, int buf_size){    int pic_found  = pc->frame_start_found;    uint32_t state = pc->state;    int cur = 0;     if (!pic_found) {        for (; cur < buf_size; ++cur) {            state = (state << 8) | buf[cur];            if ((state & 0xFFFFFF00) == 0x100 && AVS2_ISPIC(buf[cur])) {                cur++;                pic_found = 1;                break;            }        }    }     if (pic_found) {        if (!buf_size)            return END_NOT_FOUND;        for (; cur < buf_size; cur++) {            state = (state << 8) | buf[cur];            if ((state & 0xFFFFFF00) == 0x100 && AVS2_ISUNIT(buf[cur])) {                pc->frame_start_found = 0;                pc->state = -1;                return cur - 3;            }        }    }     pc->frame_start_found = pic_found;    pc->state = state;     return END_NOT_FOUND;} static void parse_avs2_seq_header(AVCodecParserContext *s, const uint8_t *buf,                                 int buf_size, AVCodecContext *avctx){    GetBitContext gb;    int profile, level;    int width, height;    int chroma, sample_precision, encoding_precision = 1;    // sample_precision and encoding_precision is 3 bits    static const uint8_t precision[8] = { 0, 8, 10 };    unsigned aspect_ratio;    unsigned frame_rate_code;    int low_delay;    av_unused int ret;    // update buf_size_min if parse more deeper    const int buf_size_min = 15;     if (buf_size < buf_size_min)        return;     ret = init_get_bits8(&gb, buf, buf_size_min);    av_assert1(ret >= 0);     s->key_frame = 1;    s->pict_type = AV_PICTURE_TYPE_I;     profile = get_bits(&gb, 8);    level = get_bits(&gb, 8);     // progressive_sequence     u(1)    // field_coded_sequence     u(1)    skip_bits(&gb, 2);     width = get_bits(&gb, 14);    height = get_bits(&gb, 14);     chroma = get_bits(&gb, 2);    sample_precision = get_bits(&gb, 3);    if (profile == AVS2_PROFILE_MAIN10)        encoding_precision = get_bits(&gb, 3);     aspect_ratio = get_bits(&gb, 4);    frame_rate_code = get_bits(&gb, 4);     // bit_rate_lower       u(18)    // marker_bit           f(1)    // bit_rate_upper       u(12)    skip_bits(&gb, 31);     low_delay = get_bits(&gb, 1);     s->width = width;    s->height = height;    s->coded_width = FFALIGN(width, 8);    s->coded_height = FFALIGN(height, 8);    avctx->framerate.num =        ff_avs2_frame_rate_tab[frame_rate_code].num;    avctx->framerate.den =        ff_avs2_frame_rate_tab[frame_rate_code].den;    avctx->has_b_frames = FFMAX(avctx->has_b_frames, !low_delay);     av_log(avctx, AV_LOG_DEBUG,           "AVS2 parse seq HDR: profile %x, level %x, "           "width %d, height %d, "           "chroma %d, sample_precision %d bits, encoding_precision %d bits, "           "aspect_ratio 0x%x, framerate %d/%d, low_delay %d\n",           profile, level,           width, height,           chroma, precision[sample_precision], precision[encoding_precision],           aspect_ratio, avctx->framerate.num, avctx->framerate.den, low_delay);} static void parse_avs2_units(AVCodecParserContext *s, const uint8_t *buf,                             int buf_size, AVCodecContext *avctx){    if (buf_size < 5)        return;     if (!(buf[0] == 0x0 && buf[1] == 0x0 && buf[2] == 0x1))        return;     switch (buf[3]) {    case AVS2_SEQ_START_CODE:        parse_avs2_seq_header(s, buf + 4, buf_size - 4, avctx);        return;    case AVS2_INTRA_PIC_START_CODE:        s->key_frame = 1;        s->pict_type = AV_PICTURE_TYPE_I;        return;    case AVS2_INTER_PIC_START_CODE:        s->key_frame = 0;        if (buf_size > 9) {            int pic_code_type = buf[8] & 0x3;            if (pic_code_type == 1)                s->pict_type = AV_PICTURE_TYPE_P;            else if (pic_code_type == 3)                s->pict_type = AV_PICTURE_TYPE_S;            else                s->pict_type = AV_PICTURE_TYPE_B;        }        return;    }} static int avs2_parse(AVCodecParserContext *s, AVCodecContext *avctx,                      const uint8_t **poutbuf, int *poutbuf_size,                      const uint8_t *buf, int buf_size){    ParseContext *pc = s->priv_data;    int next;     if (s->flags & PARSER_FLAG_COMPLETE_FRAMES)  {        next = buf_size;    } else {        next = avs2_find_frame_end(pc, buf, buf_size);        if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {            *poutbuf = NULL;            *poutbuf_size = 0;            return buf_size;        }    }     parse_avs2_units(s, buf, buf_size, avctx);     *poutbuf = buf;    *poutbuf_size = buf_size;     return next;} const AVCodecParser ff_avs2_parser = {    .codec_ids      = { AV_CODEC_ID_AVS2 },    .priv_data_size = sizeof(ParseContext),    .parser_parse   = avs2_parse,    .parser_close   = ff_parse_close,};