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/* * Copyright (c) 2012 Andrew D'Addesio * Copyright (c) 2013-2014 Mozilla Corporation * * 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 * Opus decoder/parser shared code */ #include "libavutil/attributes.h"#include "libavutil/channel_layout.h"#include "libavutil/error.h"#include "libavutil/intreadwrite.h"#include "libavutil/log.h"#include "libavutil/mem.h" #include "avcodec.h"#include "internal.h"#include "mathops.h"#include "opus.h"#include "parse.h"#include "vorbis_data.h" static const uint16_t opus_frame_duration[32] = {    480, 960, 1920, 2880,    480, 960, 1920, 2880,    480, 960, 1920, 2880,    480, 960,    480, 960,    120, 240,  480,  960,    120, 240,  480,  960,    120, 240,  480,  960,    120, 240,  480,  960,}; /** * Read a 1- or 2-byte frame length */static inline int xiph_lacing_16bit(const uint8_t **ptr, const uint8_t *end){    int val;     if (*ptr >= end)        return AVERROR_INVALIDDATA;    val = *(*ptr)++;    if (val >= 252) {        if (*ptr >= end)            return AVERROR_INVALIDDATA;        val += 4 * *(*ptr)++;    }    return val;} /** * Read a multi-byte length (used for code 3 packet padding size) */static inline int xiph_lacing_full(const uint8_t **ptr, const uint8_t *end){    int val = 0;    int next;     while (1) {        if (*ptr >= end || val > INT_MAX - 254)            return AVERROR_INVALIDDATA;        next = *(*ptr)++;        val += next;        if (next < 255)            break;        else            val--;    }    return val;} /** * Parse Opus packet info from raw packet data */int ff_opus_parse_packet(OpusPacket *pkt, const uint8_t *buf, int buf_size,                         int self_delimiting){    const uint8_t *ptr = buf;    const uint8_t *end = buf + buf_size;    int padding = 0;    int frame_bytes, i;     if (buf_size < 1)        goto fail;     /* TOC byte */    i = *ptr++;    pkt->code   = (i     ) & 0x3;    pkt->stereo = (i >> 2) & 0x1;    pkt->config = (i >> 3) & 0x1F;     /* code 2 and code 3 packets have at least 1 byte after the TOC */    if (pkt->code >= 2 && buf_size < 2)        goto fail;     switch (pkt->code) {    case 0:        /* 1 frame */        pkt->frame_count = 1;        pkt->vbr         = 0;         if (self_delimiting) {            int len = xiph_lacing_16bit(&ptr, end);            if (len < 0 || len > end - ptr)                goto fail;            end      = ptr + len;            buf_size = end - buf;        }         frame_bytes = end - ptr;        if (frame_bytes > OPUS_MAX_FRAME_SIZE)            goto fail;        pkt->frame_offset[0] = ptr - buf;        pkt->frame_size[0]   = frame_bytes;        break;    case 1:        /* 2 frames, equal size */        pkt->frame_count = 2;        pkt->vbr         = 0;         if (self_delimiting) {            int len = xiph_lacing_16bit(&ptr, end);            if (len < 0 || 2 * len > end - ptr)                goto fail;            end      = ptr + 2 * len;            buf_size = end - buf;        }         frame_bytes = end - ptr;        if (frame_bytes & 1 || frame_bytes >> 1 > OPUS_MAX_FRAME_SIZE)            goto fail;        pkt->frame_offset[0] = ptr - buf;        pkt->frame_size[0]   = frame_bytes >> 1;        pkt->frame_offset[1] = pkt->frame_offset[0] + pkt->frame_size[0];        pkt->frame_size[1]   = frame_bytes >> 1;        break;    case 2:        /* 2 frames, different sizes */        pkt->frame_count = 2;        pkt->vbr         = 1;         /* read 1st frame size */        frame_bytes = xiph_lacing_16bit(&ptr, end);        if (frame_bytes < 0)            goto fail;         if (self_delimiting) {            int len = xiph_lacing_16bit(&ptr, end);            if (len < 0 || len + frame_bytes > end - ptr)                goto fail;            end      = ptr + frame_bytes + len;            buf_size = end - buf;        }         pkt->frame_offset[0] = ptr - buf;        pkt->frame_size[0]   = frame_bytes;         /* calculate 2nd frame size */        frame_bytes = end - ptr - pkt->frame_size[0];        if (frame_bytes < 0 || frame_bytes > OPUS_MAX_FRAME_SIZE)            goto fail;        pkt->frame_offset[1] = pkt->frame_offset[0] + pkt->frame_size[0];        pkt->frame_size[1]   = frame_bytes;        break;    case 3:        /* 1 to 48 frames, can be different sizes */        i = *ptr++;        pkt->frame_count = (i     ) & 0x3F;        padding          = (i >> 6) & 0x01;        pkt->vbr         = (i >> 7) & 0x01;         if (pkt->frame_count == 0 || pkt->frame_count > OPUS_MAX_FRAMES)            goto fail;         /* read padding size */        if (padding) {            padding = xiph_lacing_full(&ptr, end);            if (padding < 0)                goto fail;        }         /* read frame sizes */        if (pkt->vbr) {            /* for VBR, all frames except the final one have their size coded               in the bitstream. the last frame size is implicit. */            int total_bytes = 0;            for (i = 0; i < pkt->frame_count - 1; i++) {                frame_bytes = xiph_lacing_16bit(&ptr, end);                if (frame_bytes < 0)                    goto fail;                pkt->frame_size[i] = frame_bytes;                total_bytes += frame_bytes;            }             if (self_delimiting) {                int len = xiph_lacing_16bit(&ptr, end);                if (len < 0 || len + total_bytes + padding > end - ptr)                    goto fail;                end      = ptr + total_bytes + len + padding;                buf_size = end - buf;            }             frame_bytes = end - ptr - padding;            if (total_bytes > frame_bytes)                goto fail;            pkt->frame_offset[0] = ptr - buf;            for (i = 1; i < pkt->frame_count; i++)                pkt->frame_offset[i] = pkt->frame_offset[i-1] + pkt->frame_size[i-1];            pkt->frame_size[pkt->frame_count-1] = frame_bytes - total_bytes;        } else {            /* for CBR, the remaining packet bytes are divided evenly between               the frames */            if (self_delimiting) {                frame_bytes = xiph_lacing_16bit(&ptr, end);                if (frame_bytes < 0 || pkt->frame_count * frame_bytes + padding > end - ptr)                    goto fail;                end      = ptr + pkt->frame_count * frame_bytes + padding;                buf_size = end - buf;            } else {                frame_bytes = end - ptr - padding;                if (frame_bytes % pkt->frame_count ||                    frame_bytes / pkt->frame_count > OPUS_MAX_FRAME_SIZE)                    goto fail;                frame_bytes /= pkt->frame_count;            }             pkt->frame_offset[0] = ptr - buf;            pkt->frame_size[0]   = frame_bytes;            for (i = 1; i < pkt->frame_count; i++) {                pkt->frame_offset[i] = pkt->frame_offset[i-1] + pkt->frame_size[i-1];                pkt->frame_size[i]   = frame_bytes;            }        }    }     pkt->packet_size = buf_size;    pkt->data_size   = pkt->packet_size - padding;     /* total packet duration cannot be larger than 120ms */    pkt->frame_duration = opus_frame_duration[pkt->config];    if (pkt->frame_duration * pkt->frame_count > OPUS_MAX_PACKET_DUR)        goto fail;     /* set mode and bandwidth */    if (pkt->config < 12) {        pkt->mode = OPUS_MODE_SILK;        pkt->bandwidth = pkt->config >> 2;    } else if (pkt->config < 16) {        pkt->mode = OPUS_MODE_HYBRID;        pkt->bandwidth = OPUS_BANDWIDTH_SUPERWIDEBAND + (pkt->config >= 14);    } else {        pkt->mode = OPUS_MODE_CELT;        pkt->bandwidth = (pkt->config - 16) >> 2;        /* skip medium band */        if (pkt->bandwidth)            pkt->bandwidth++;    }     return 0; fail:    memset(pkt, 0, sizeof(*pkt));    return AVERROR_INVALIDDATA;} static int channel_reorder_vorbis(int nb_channels, int channel_idx){    return ff_vorbis_channel_layout_offsets[nb_channels - 1][channel_idx];} static int channel_reorder_unknown(int nb_channels, int channel_idx){    return channel_idx;} av_cold int ff_opus_parse_extradata(AVCodecContext *avctx,                                    OpusParseContext *s){    static const uint8_t default_channel_map[2] = { 0, 1 };     int (*channel_reorder)(int, int) = channel_reorder_unknown;    int channels = avctx->ch_layout.nb_channels;     const uint8_t *extradata, *channel_map;    int extradata_size;    int version, map_type, streams, stereo_streams, i, j, ret;    AVChannelLayout layout = { 0 };     if (!avctx->extradata) {        if (channels > 2) {            av_log(avctx, AV_LOG_ERROR,                   "Multichannel configuration without extradata.\n");            return AVERROR(EINVAL);        }        extradata      = opus_default_extradata;        extradata_size = sizeof(opus_default_extradata);    } else {        extradata = avctx->extradata;        extradata_size = avctx->extradata_size;    }     if (extradata_size < 19) {        av_log(avctx, AV_LOG_ERROR, "Invalid extradata size: %d\n",               extradata_size);        return AVERROR_INVALIDDATA;    }     version = extradata[8];    if (version > 15) {        avpriv_request_sample(avctx, "Extradata version %d", version);        return AVERROR_PATCHWELCOME;    }     avctx->delay = AV_RL16(extradata + 10);    if (avctx->internal)        avctx->internal->skip_samples = avctx->delay;     channels = avctx->extradata ? extradata[9] : (channels == 1) ? 1 : 2;    if (!channels) {        av_log(avctx, AV_LOG_ERROR, "Zero channel count specified in the extradata\n");        return AVERROR_INVALIDDATA;    }     s->gain_i = AV_RL16(extradata + 16);     map_type = extradata[18];    if (!map_type) {        if (channels > 2) {            av_log(avctx, AV_LOG_ERROR,                   "Channel mapping 0 is only specified for up to 2 channels\n");            ret = AVERROR_INVALIDDATA;            goto fail;        }        layout         = (channels == 1) ? (AVChannelLayout)AV_CHANNEL_LAYOUT_MONO :                                           (AVChannelLayout)AV_CHANNEL_LAYOUT_STEREO;        streams        = 1;        stereo_streams = channels - 1;        channel_map    = default_channel_map;    } else if (map_type == 1 || map_type == 2 || map_type == 255) {        if (extradata_size < 21 + channels) {            av_log(avctx, AV_LOG_ERROR, "Invalid extradata size: %d\n",                   extradata_size);            ret = AVERROR_INVALIDDATA;            goto fail;        }         streams        = extradata[19];        stereo_streams = extradata[20];        if (!streams || stereo_streams > streams ||            streams + stereo_streams > 255) {            av_log(avctx, AV_LOG_ERROR,                   "Invalid stream/stereo stream count: %d/%d\n", streams, stereo_streams);            ret = AVERROR_INVALIDDATA;            goto fail;        }         if (map_type == 1) {            if (channels > 8) {                av_log(avctx, AV_LOG_ERROR,                       "Channel mapping 1 is only specified for up to 8 channels\n");                ret = AVERROR_INVALIDDATA;                goto fail;            }            av_channel_layout_copy(&layout, &ff_vorbis_ch_layouts[channels - 1]);            channel_reorder = channel_reorder_vorbis;        } else if (map_type == 2) {            int ambisonic_order = ff_sqrt(channels) - 1;            if (channels != ((ambisonic_order + 1) * (ambisonic_order + 1)) &&                channels != ((ambisonic_order + 1) * (ambisonic_order + 1) + 2)) {                av_log(avctx, AV_LOG_ERROR,                       "Channel mapping 2 is only specified for channel counts"                       " which can be written as (n + 1)^2 or (n + 1)^2 + 2"                       " for nonnegative integer n\n");                ret = AVERROR_INVALIDDATA;                goto fail;            }            if (channels > 227) {                av_log(avctx, AV_LOG_ERROR, "Too many channels\n");                ret = AVERROR_INVALIDDATA;                goto fail;            }             layout.order = AV_CHANNEL_ORDER_AMBISONIC;            layout.nb_channels = channels;            if (channels != ((ambisonic_order + 1) * (ambisonic_order + 1)))                layout.u.mask = AV_CH_LAYOUT_STEREO;        } else {            layout.order       = AV_CHANNEL_ORDER_UNSPEC;            layout.nb_channels = channels;        }         channel_map = extradata + 21;    } else {        avpriv_request_sample(avctx, "Mapping type %d", map_type);        return AVERROR_PATCHWELCOME;    }     s->channel_maps = av_calloc(channels, sizeof(*s->channel_maps));    if (!s->channel_maps) {        ret = AVERROR(ENOMEM);        goto fail;    }     for (i = 0; i < channels; i++) {        ChannelMap *map = &s->channel_maps[i];        uint8_t     idx = channel_map[channel_reorder(channels, i)];         if (idx == 255) {            map->silence = 1;            continue;        } else if (idx >= streams + stereo_streams) {            av_log(avctx, AV_LOG_ERROR,                   "Invalid channel map for output channel %d: %d\n", i, idx);            av_freep(&s->channel_maps);            ret = AVERROR_INVALIDDATA;            goto fail;        }         /* check that we did not see this index yet */        map->copy = 0;        for (j = 0; j < i; j++)            if (channel_map[channel_reorder(channels, j)] == idx) {                map->copy     = 1;                map->copy_idx = j;                break;            }         if (idx < 2 * stereo_streams) {            map->stream_idx  = idx / 2;            map->channel_idx = idx & 1;        } else {            map->stream_idx  = idx - stereo_streams;            map->channel_idx = 0;        }    }     ret = av_channel_layout_copy(&avctx->ch_layout, &layout);    if (ret < 0)        goto fail;     s->nb_streams         = streams;    s->nb_stereo_streams  = stereo_streams;     return 0;fail:    av_channel_layout_uninit(&layout);    return ret;}

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