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/*
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 * Copyright (c) 2006 Paul Richards <paul.richards@gmail.com>
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 *
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 * This file is part of Libav.
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 *
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 * Libav is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * Libav is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with Libav; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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/**
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 * @file
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 * @brief Theora encoder using libtheora.
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 * @author Paul Richards <paul.richards@gmail.com>
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 *
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 * A lot of this is copy / paste from other output codecs in
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 * libavcodec or pure guesswork (or both).
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 *
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 * I have used t_ prefixes on variables which are libtheora types
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 * and o_ prefixes on variables which are libogg types.
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 */
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/* FFmpeg includes */
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#include "libavutil/intreadwrite.h"
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#include "libavutil/log.h"
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#include "libavutil/base64.h"
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#include "avcodec.h"
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/* libtheora includes */
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#include <theora/theoraenc.h>
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typedef struct TheoraContext {
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    th_enc_ctx *t_state;
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    uint8_t    *stats;
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    int         stats_size;
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    int         stats_offset;
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    int         uv_hshift;
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    int         uv_vshift;
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    int         keyframe_mask;
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} TheoraContext;
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/** Concatenate an ogg_packet into the extradata. */
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static int concatenate_packet(unsigned int* offset,
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                              AVCodecContext* avc_context,
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                              const ogg_packet* packet)
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{
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    const char* message = NULL;
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    uint8_t* newdata    = NULL;
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    int newsize = avc_context->extradata_size + 2 + packet->bytes;
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    if (packet->bytes < 0) {
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        message = "ogg_packet has negative size";
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    } else if (packet->bytes > 0xffff) {
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        message = "ogg_packet is larger than 65535 bytes";
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    } else if (newsize < avc_context->extradata_size) {
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        message = "extradata_size would overflow";
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    } else {
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        newdata = av_realloc(avc_context->extradata, newsize);
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        if (!newdata)
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            message = "av_realloc failed";
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    }
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    if (message) {
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        av_log(avc_context, AV_LOG_ERROR, "concatenate_packet failed: %s\n", message);
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        return -1;
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    }
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    avc_context->extradata      = newdata;
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    avc_context->extradata_size = newsize;
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    AV_WB16(avc_context->extradata + (*offset), packet->bytes);
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    *offset += 2;
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    memcpy(avc_context->extradata + (*offset), packet->packet, packet->bytes);
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    (*offset) += packet->bytes;
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    return 0;
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}
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static int get_stats(AVCodecContext *avctx, int eos)
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{
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#ifdef TH_ENCCTL_2PASS_OUT
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    TheoraContext *h = avctx->priv_data;
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    uint8_t *buf;
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    int bytes;
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    bytes = th_encode_ctl(h->t_state, TH_ENCCTL_2PASS_OUT, &buf, sizeof(buf));
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    if (bytes < 0) {
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        av_log(avctx, AV_LOG_ERROR, "Error getting first pass stats\n");
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        return -1;
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    }
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    if (!eos) {
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        h->stats = av_fast_realloc(h->stats, &h->stats_size,
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                                   h->stats_offset + bytes);
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        memcpy(h->stats + h->stats_offset, buf, bytes);
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        h->stats_offset += bytes;
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    } else {
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        int b64_size = AV_BASE64_SIZE(h->stats_offset);
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        // libtheora generates a summary header at the end
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        memcpy(h->stats, buf, bytes);
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        avctx->stats_out = av_malloc(b64_size);
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        av_base64_encode(avctx->stats_out, b64_size, h->stats, h->stats_offset);
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    }
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    return 0;
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#else
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    av_log(avctx, AV_LOG_ERROR, "libtheora too old to support 2pass\n");
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    return -1;
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#endif
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}
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// libtheora won't read the entire buffer we give it at once, so we have to
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// repeatedly submit it...
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static int submit_stats(AVCodecContext *avctx)
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{
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#ifdef TH_ENCCTL_2PASS_IN
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    TheoraContext *h = avctx->priv_data;
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    int bytes;
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    if (!h->stats) {
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        if (!avctx->stats_in) {
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            av_log(avctx, AV_LOG_ERROR, "No statsfile for second pass\n");
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            return -1;
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        }
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        h->stats_size = strlen(avctx->stats_in) * 3/4;
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        h->stats      = av_malloc(h->stats_size);
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        h->stats_size = av_base64_decode(h->stats, avctx->stats_in, h->stats_size);
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    }
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    while (h->stats_size - h->stats_offset > 0) {
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        bytes = th_encode_ctl(h->t_state, TH_ENCCTL_2PASS_IN,
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                              h->stats + h->stats_offset,
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                              h->stats_size - h->stats_offset);
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        if (bytes < 0) {
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            av_log(avctx, AV_LOG_ERROR, "Error submitting stats\n");
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            return -1;
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        }
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        if (!bytes)
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            return 0;
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        h->stats_offset += bytes;
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    }
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    return 0;
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#else
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    av_log(avctx, AV_LOG_ERROR, "libtheora too old to support 2pass\n");
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    return -1;
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#endif
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}
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static av_cold int encode_init(AVCodecContext* avc_context)
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{
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    th_info t_info;
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    th_comment t_comment;
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    ogg_packet o_packet;
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    unsigned int offset;
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    TheoraContext *h = avc_context->priv_data;
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    uint32_t gop_size = avc_context->gop_size;
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    /* Set up the theora_info struct */
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    th_info_init(&t_info);
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    t_info.frame_width  = FFALIGN(avc_context->width,  16);
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    t_info.frame_height = FFALIGN(avc_context->height, 16);
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    t_info.pic_width    = avc_context->width;
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    t_info.pic_height   = avc_context->height;
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    t_info.pic_x        = 0;
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    t_info.pic_y        = 0;
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    /* Swap numerator and denominator as time_base in AVCodecContext gives the
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     * time period between frames, but theora_info needs the framerate.  */
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    t_info.fps_numerator   = avc_context->time_base.den;
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    t_info.fps_denominator = avc_context->time_base.num;
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    if (avc_context->sample_aspect_ratio.num) {
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        t_info.aspect_numerator   = avc_context->sample_aspect_ratio.num;
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        t_info.aspect_denominator = avc_context->sample_aspect_ratio.den;
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    } else {
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        t_info.aspect_numerator   = 1;
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        t_info.aspect_denominator = 1;
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    }
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    if (avc_context->color_primaries == AVCOL_PRI_BT470M)
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        t_info.colorspace = TH_CS_ITU_REC_470M;
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    else if (avc_context->color_primaries == AVCOL_PRI_BT470BG)
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        t_info.colorspace = TH_CS_ITU_REC_470BG;
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    else
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        t_info.colorspace = TH_CS_UNSPECIFIED;
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    if (avc_context->pix_fmt == PIX_FMT_YUV420P)
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        t_info.pixel_fmt = TH_PF_420;
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    else if (avc_context->pix_fmt == PIX_FMT_YUV422P)
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        t_info.pixel_fmt = TH_PF_422;
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    else if (avc_context->pix_fmt == PIX_FMT_YUV444P)
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        t_info.pixel_fmt = TH_PF_444;
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    else {
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        av_log(avc_context, AV_LOG_ERROR, "Unsupported pix_fmt\n");
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        return -1;
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    }
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    avcodec_get_chroma_sub_sample(avc_context->pix_fmt, &h->uv_hshift, &h->uv_vshift);
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    if (avc_context->flags & CODEC_FLAG_QSCALE) {
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        /* to be constant with the libvorbis implementation, clip global_quality to 0 - 10
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           Theora accepts a quality parameter p, which is:
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                * 0 <= p <=63
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                * an int value
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         */
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        t_info.quality        = av_clip(avc_context->global_quality / (float)FF_QP2LAMBDA, 0, 10) * 6.3;
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        t_info.target_bitrate = 0;
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    } else {
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        t_info.target_bitrate = avc_context->bit_rate;
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        t_info.quality        = 0;
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    }
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    /* Now initialise libtheora */
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    h->t_state = th_encode_alloc(&t_info);
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    if (!h->t_state) {
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        av_log(avc_context, AV_LOG_ERROR, "theora_encode_init failed\n");
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        return -1;
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    }
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    h->keyframe_mask = (1 << t_info.keyframe_granule_shift) - 1;
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    /* Clear up theora_info struct */
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    th_info_clear(&t_info);
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    if (th_encode_ctl(h->t_state, TH_ENCCTL_SET_KEYFRAME_FREQUENCY_FORCE,
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                      &gop_size, sizeof(gop_size))) {
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        av_log(avc_context, AV_LOG_ERROR, "Error setting GOP size\n");
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        return -1;
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    }
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    // need to enable 2 pass (via TH_ENCCTL_2PASS_) before encoding headers
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    if (avc_context->flags & CODEC_FLAG_PASS1) {
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        if (get_stats(avc_context, 0))
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            return -1;
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    } else if (avc_context->flags & CODEC_FLAG_PASS2) {
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        if (submit_stats(avc_context))
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            return -1;
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    }
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    /*
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        Output first header packet consisting of theora
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        header, comment, and tables.
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        Each one is prefixed with a 16bit size, then they
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        are concatenated together into ffmpeg's extradata.
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    */
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    offset = 0;
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    /* Headers */
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    th_comment_init(&t_comment);
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    while (th_encode_flushheader(h->t_state, &t_comment, &o_packet))
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        if (concatenate_packet(&offset, avc_context, &o_packet))
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            return -1;
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    th_comment_clear(&t_comment);
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    /* Set up the output AVFrame */
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    avc_context->coded_frame= avcodec_alloc_frame();
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    return 0;
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}
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static int encode_frame(AVCodecContext* avc_context, uint8_t *outbuf,
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                        int buf_size, void *data)
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{
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    th_ycbcr_buffer t_yuv_buffer;
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    TheoraContext *h = avc_context->priv_data;
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    AVFrame *frame = data;
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    ogg_packet o_packet;
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    int result, i;
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    // EOS, finish and get 1st pass stats if applicable
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    if (!frame) {
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        th_encode_packetout(h->t_state, 1, &o_packet);
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        if (avc_context->flags & CODEC_FLAG_PASS1)
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            if (get_stats(avc_context, 1))
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                return -1;
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        return 0;
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    }
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    /* Copy planes to the theora yuv_buffer */
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    for (i = 0; i < 3; i++) {
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        t_yuv_buffer[i].width  = FFALIGN(avc_context->width,  16) >> (i && h->uv_hshift);
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        t_yuv_buffer[i].height = FFALIGN(avc_context->height, 16) >> (i && h->uv_vshift);
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        t_yuv_buffer[i].stride = frame->linesize[i];
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        t_yuv_buffer[i].data   = frame->data[i];
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    }
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    if (avc_context->flags & CODEC_FLAG_PASS2)
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        if (submit_stats(avc_context))
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            return -1;
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    /* Now call into theora_encode_YUVin */
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    result = th_encode_ycbcr_in(h->t_state, t_yuv_buffer);
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    if (result) {
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        const char* message;
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        switch (result) {
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        case -1:
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            message = "differing frame sizes";
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            break;
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        case TH_EINVAL:
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            message = "encoder is not ready or is finished";
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            break;
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        default:
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            message = "unknown reason";
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            break;
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        }
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        av_log(avc_context, AV_LOG_ERROR, "theora_encode_YUVin failed (%s) [%d]\n", message, result);
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        return -1;
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    }
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    if (avc_context->flags & CODEC_FLAG_PASS1)
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        if (get_stats(avc_context, 0))
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            return -1;
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    /* Pick up returned ogg_packet */
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    result = th_encode_packetout(h->t_state, 0, &o_packet);
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    switch (result) {
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    case 0:
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        /* No packet is ready */
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        return 0;
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    case 1:
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        /* Success, we have a packet */
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        break;
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    default:
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        av_log(avc_context, AV_LOG_ERROR, "theora_encode_packetout failed [%d]\n", result);
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        return -1;
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    }
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    /* Copy ogg_packet content out to buffer */
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    if (buf_size < o_packet.bytes) {
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        av_log(avc_context, AV_LOG_ERROR, "encoded frame too large\n");
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        return -1;
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    }
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    memcpy(outbuf, o_packet.packet, o_packet.bytes);
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    // HACK: assumes no encoder delay, this is true until libtheora becomes
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    // multithreaded (which will be disabled unless explictly requested)
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    avc_context->coded_frame->pts = frame->pts;
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    avc_context->coded_frame->key_frame = !(o_packet.granulepos & h->keyframe_mask);
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    return o_packet.bytes;
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}
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static av_cold int encode_close(AVCodecContext* avc_context)
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{
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    TheoraContext *h = avc_context->priv_data;
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    th_encode_free(h->t_state);
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    av_freep(&h->stats);
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    av_freep(&avc_context->coded_frame);
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    av_freep(&avc_context->stats_out);
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    av_freep(&avc_context->extradata);
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    avc_context->extradata_size = 0;
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    return 0;
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}
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/** AVCodec struct exposed to libavcodec */
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AVCodec ff_libtheora_encoder = {
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    .name = "libtheora",
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    .type = AVMEDIA_TYPE_VIDEO,
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    .id = CODEC_ID_THEORA,
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    .priv_data_size = sizeof(TheoraContext),
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    .init = encode_init,
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    .close = encode_close,
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    .encode = encode_frame,
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    .capabilities = CODEC_CAP_DELAY, // needed to get the statsfile summary
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    .pix_fmts= (const enum PixelFormat[]){PIX_FMT_YUV420P, PIX_FMT_YUV422P, PIX_FMT_YUV444P, PIX_FMT_NONE},
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    .long_name = NULL_IF_CONFIG_SMALL("libtheora Theora"),
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};