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ffmpeg / libavcodec / h264_mp4toannexb_bsf.c @ 4e84f994

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1 bdfae2a5 Benoit Fouet
/*
2 ec21c215 Alex Converse
 * H.264 MP4 to Annex B byte stream format filter
3 074bfa7d Benoit Fouet
 * Copyright (c) 2007 Benoit Fouet <benoit.fouet@free.fr>
4 bdfae2a5 Benoit Fouet
 *
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 * This file is part of FFmpeg.
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 *
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 * FFmpeg 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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 * FFmpeg 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 FFmpeg; 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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22 6a5d31ac Diego Biurrun
#include "libavutil/intreadwrite.h"
23 bdfae2a5 Benoit Fouet
#include "avcodec.h"
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typedef struct H264BSFContext {
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    uint8_t  length_size;
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    uint8_t  first_idr;
28 d5cc1ed7 Luca Abeni
    int      extradata_parsed;
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} H264BSFContext;
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31 639c697c Benoit Fouet
static int alloc_and_copy(uint8_t **poutbuf,          int *poutbuf_size,
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                          const uint8_t *sps_pps, uint32_t sps_pps_size,
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                          const uint8_t *in,      uint32_t in_size) {
34 bdfae2a5 Benoit Fouet
    uint32_t offset = *poutbuf_size;
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    uint8_t nal_header_size = offset ? 3 : 4;
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    void *tmp;
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    *poutbuf_size += sps_pps_size+in_size+nal_header_size;
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    tmp = av_realloc(*poutbuf, *poutbuf_size);
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    if (!tmp)
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        return AVERROR(ENOMEM);
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    *poutbuf = tmp;
43 bdfae2a5 Benoit Fouet
    if (sps_pps)
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        memcpy(*poutbuf+offset, sps_pps, sps_pps_size);
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    memcpy(*poutbuf+sps_pps_size+nal_header_size+offset, in, in_size);
46 1f7d2f54 Benoit Fouet
    if (!offset) {
47 bdfae2a5 Benoit Fouet
        AV_WB32(*poutbuf+sps_pps_size, 1);
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    } else {
49 48aecf5a Andreas Öman
        (*poutbuf+offset+sps_pps_size)[0] = (*poutbuf+offset+sps_pps_size)[1] = 0;
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        (*poutbuf+offset+sps_pps_size)[2] = 1;
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    }
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    return 0;
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}
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static int h264_mp4toannexb_filter(AVBitStreamFilterContext *bsfc,
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                                   AVCodecContext *avctx, const char *args,
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                                   uint8_t  **poutbuf, int *poutbuf_size,
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                                   const uint8_t *buf, int      buf_size,
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                                   int keyframe) {
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    H264BSFContext *ctx = bsfc->priv_data;
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    uint8_t unit_type;
63 52486603 Thomas Devanneaux
    int32_t nal_size;
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    uint32_t cumul_size = 0;
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    const uint8_t *buf_end = buf + buf_size;
66 bdfae2a5 Benoit Fouet
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    /* nothing to filter */
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    if (!avctx->extradata || avctx->extradata_size < 6) {
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        *poutbuf = (uint8_t*) buf;
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        *poutbuf_size = buf_size;
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        return 0;
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    }
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    /* retrieve sps and pps NAL units from extradata */
75 d5cc1ed7 Luca Abeni
    if (!ctx->extradata_parsed) {
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        uint16_t unit_size;
77 d5cc1ed7 Luca Abeni
        uint64_t total_size = 0;
78 02dd3666 Sean McGovern
        uint8_t *out = NULL, unit_nb, sps_done = 0, sps_seen = 0, pps_seen = 0;
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        const uint8_t *extradata = avctx->extradata+4;
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        static const uint8_t nalu_header[4] = {0, 0, 0, 1};
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        /* retrieve length coded size */
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        ctx->length_size = (*extradata++ & 0x3) + 1;
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        if (ctx->length_size == 3)
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            return AVERROR(EINVAL);
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        /* retrieve sps and pps unit(s) */
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        unit_nb = *extradata++ & 0x1f; /* number of sps unit(s) */
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        if (!unit_nb) {
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            unit_nb = *extradata++; /* number of pps unit(s) */
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            sps_done++;
92 02dd3666 Sean McGovern
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            if (unit_nb)
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                pps_seen = 1;
95 4e84f994 Ronald S. Bultje
        } else {
96 02dd3666 Sean McGovern
            sps_seen = 1;
97 bdfae2a5 Benoit Fouet
        }
98 02dd3666 Sean McGovern
99 bdfae2a5 Benoit Fouet
        while (unit_nb--) {
100 639c697c Benoit Fouet
            void *tmp;
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102 bdfae2a5 Benoit Fouet
            unit_size = AV_RB16(extradata);
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            total_size += unit_size+4;
104 bb5cfc48 Benoit Fouet
            if (total_size > INT_MAX - FF_INPUT_BUFFER_PADDING_SIZE ||
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                extradata+2+unit_size > avctx->extradata+avctx->extradata_size) {
106 bdfae2a5 Benoit Fouet
                av_free(out);
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                return AVERROR(EINVAL);
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            }
109 639c697c Benoit Fouet
            tmp = av_realloc(out, total_size + FF_INPUT_BUFFER_PADDING_SIZE);
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            if (!tmp) {
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                av_free(out);
112 bdfae2a5 Benoit Fouet
                return AVERROR(ENOMEM);
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            }
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            out = tmp;
115 bdfae2a5 Benoit Fouet
            memcpy(out+total_size-unit_size-4, nalu_header, 4);
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            memcpy(out+total_size-unit_size,   extradata+2, unit_size);
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            extradata += 2+unit_size;
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            if (!unit_nb && !sps_done++)
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                unit_nb = *extradata++; /* number of pps unit(s) */
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        }
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123 02dd3666 Sean McGovern
        if(out)
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            memset(out + total_size, 0, FF_INPUT_BUFFER_PADDING_SIZE);
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        if (!sps_seen)
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            av_log(avctx, AV_LOG_WARNING, "Warning: SPS NALU missing or invalid. The resulting stream may not play.\n");
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        if (!pps_seen)
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            av_log(avctx, AV_LOG_WARNING, "Warning: PPS NALU missing or invalid. The resulting stream may not play.\n");
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131 d5cc1ed7 Luca Abeni
        av_free(avctx->extradata);
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        avctx->extradata      = out;
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        avctx->extradata_size = total_size;
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        ctx->first_idr        = 1;
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        ctx->extradata_parsed = 1;
136 bdfae2a5 Benoit Fouet
    }
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    *poutbuf_size = 0;
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    *poutbuf = NULL;
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    do {
141 52486603 Thomas Devanneaux
        if (buf + ctx->length_size > buf_end)
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            goto fail;
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144 1f7d2f54 Benoit Fouet
        if (ctx->length_size == 1) {
145 bdfae2a5 Benoit Fouet
            nal_size = buf[0];
146 1f7d2f54 Benoit Fouet
        } else if (ctx->length_size == 2) {
147 bdfae2a5 Benoit Fouet
            nal_size = AV_RB16(buf);
148 1f7d2f54 Benoit Fouet
        } else
149 bdfae2a5 Benoit Fouet
            nal_size = AV_RB32(buf);
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        buf += ctx->length_size;
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        unit_type = *buf & 0x1f;
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154 52486603 Thomas Devanneaux
        if (buf + nal_size > buf_end || nal_size < 0)
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            goto fail;
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157 bdfae2a5 Benoit Fouet
        /* prepend only to the first type 5 NAL unit of an IDR picture */
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        if (ctx->first_idr && unit_type == 5) {
159 639c697c Benoit Fouet
            if (alloc_and_copy(poutbuf, poutbuf_size,
160 bb5cfc48 Benoit Fouet
                               avctx->extradata, avctx->extradata_size,
161 639c697c Benoit Fouet
                               buf, nal_size) < 0)
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                goto fail;
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            ctx->first_idr = 0;
164 1f7d2f54 Benoit Fouet
        } else {
165 639c697c Benoit Fouet
            if (alloc_and_copy(poutbuf, poutbuf_size,
166 bb5cfc48 Benoit Fouet
                               NULL, 0,
167 639c697c Benoit Fouet
                               buf, nal_size) < 0)
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                goto fail;
169 bdfae2a5 Benoit Fouet
            if (!ctx->first_idr && unit_type == 1)
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                ctx->first_idr = 1;
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        }
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        buf += nal_size;
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        cumul_size += nal_size + ctx->length_size;
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    } while (cumul_size < buf_size);
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    return 1;
178 52486603 Thomas Devanneaux
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fail:
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    av_freep(poutbuf);
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    *poutbuf_size = 0;
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    return AVERROR(EINVAL);
183 bdfae2a5 Benoit Fouet
}
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185 d36beb3f Diego Elio Pettenò
AVBitStreamFilter ff_h264_mp4toannexb_bsf = {
186 bdfae2a5 Benoit Fouet
    "h264_mp4toannexb",
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    sizeof(H264BSFContext),
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    h264_mp4toannexb_filter,
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};