LCOV - code coverage report
Current view: top level - libavcodec - h264_mp4toannexb_bsf.c (source / functions) Hit Total Coverage
Test: coverage.info Lines: 106 147 72.1 %
Date: 2017-12-15 11:05:35 Functions: 4 4 100.0 %

          Line data    Source code
       1             : /*
       2             :  * H.264 MP4 to Annex B byte stream format filter
       3             :  * Copyright (c) 2007 Benoit Fouet <benoit.fouet@free.fr>
       4             :  *
       5             :  * This file is part of FFmpeg.
       6             :  *
       7             :  * FFmpeg is free software; you can redistribute it and/or
       8             :  * modify it under the terms of the GNU Lesser General Public
       9             :  * License as published by the Free Software Foundation; either
      10             :  * version 2.1 of the License, or (at your option) any later version.
      11             :  *
      12             :  * FFmpeg is distributed in the hope that it will be useful,
      13             :  * but WITHOUT ANY WARRANTY; without even the implied warranty of
      14             :  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      15             :  * Lesser General Public License for more details.
      16             :  *
      17             :  * You should have received a copy of the GNU Lesser General Public
      18             :  * License along with FFmpeg; if not, write to the Free Software
      19             :  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
      20             :  */
      21             : 
      22             : #include <string.h>
      23             : 
      24             : #include "libavutil/intreadwrite.h"
      25             : #include "libavutil/mem.h"
      26             : 
      27             : #include "avcodec.h"
      28             : #include "bsf.h"
      29             : 
      30             : typedef struct H264BSFContext {
      31             :     int32_t  sps_offset;
      32             :     int32_t  pps_offset;
      33             :     uint8_t  length_size;
      34             :     uint8_t  new_idr;
      35             :     uint8_t  idr_sps_seen;
      36             :     uint8_t  idr_pps_seen;
      37             :     int      extradata_parsed;
      38             : } H264BSFContext;
      39             : 
      40        1740 : static int alloc_and_copy(AVPacket *out,
      41             :                           const uint8_t *sps_pps, uint32_t sps_pps_size,
      42             :                           const uint8_t *in, uint32_t in_size)
      43             : {
      44        1740 :     uint32_t offset         = out->size;
      45        1740 :     uint8_t nal_header_size = offset ? 3 : 4;
      46             :     int err;
      47             : 
      48        1740 :     err = av_grow_packet(out, sps_pps_size + in_size + nal_header_size);
      49        1740 :     if (err < 0)
      50           0 :         return err;
      51             : 
      52        1740 :     if (sps_pps)
      53          14 :         memcpy(out->data + offset, sps_pps, sps_pps_size);
      54        1740 :     memcpy(out->data + sps_pps_size + nal_header_size + offset, in, in_size);
      55        1740 :     if (!offset) {
      56         398 :         AV_WB32(out->data + sps_pps_size, 1);
      57             :     } else {
      58        2684 :         (out->data + offset + sps_pps_size)[0] =
      59        2684 :         (out->data + offset + sps_pps_size)[1] = 0;
      60        1342 :         (out->data + offset + sps_pps_size)[2] = 1;
      61             :     }
      62             : 
      63        1740 :     return 0;
      64             : }
      65             : 
      66           5 : static int h264_extradata_to_annexb(AVBSFContext *ctx, const int padding)
      67             : {
      68           5 :     H264BSFContext *s = ctx->priv_data;
      69             :     uint16_t unit_size;
      70           5 :     uint64_t total_size                 = 0;
      71           5 :     uint8_t *out                        = NULL, unit_nb, sps_done = 0,
      72           5 :              sps_seen                   = 0, pps_seen = 0;
      73           5 :     const uint8_t *extradata            = ctx->par_in->extradata + 4;
      74             :     static const uint8_t nalu_header[4] = { 0, 0, 0, 1 };
      75           5 :     int length_size = (*extradata++ & 0x3) + 1; // retrieve length coded size
      76             : 
      77           5 :     s->sps_offset = s->pps_offset = -1;
      78             : 
      79             :     /* retrieve sps and pps unit(s) */
      80           5 :     unit_nb = *extradata++ & 0x1f; /* number of sps unit(s) */
      81           5 :     if (!unit_nb) {
      82           0 :         goto pps;
      83             :     } else {
      84           5 :         s->sps_offset = 0;
      85           5 :         sps_seen = 1;
      86             :     }
      87             : 
      88          20 :     while (unit_nb--) {
      89             :         int err;
      90             : 
      91          10 :         unit_size   = AV_RB16(extradata);
      92          10 :         total_size += unit_size + 4;
      93          10 :         if (total_size > INT_MAX - padding) {
      94           0 :             av_log(ctx, AV_LOG_ERROR,
      95             :                    "Too big extradata size, corrupted stream or invalid MP4/AVCC bitstream\n");
      96           0 :             av_free(out);
      97           0 :             return AVERROR(EINVAL);
      98             :         }
      99          10 :         if (extradata + 2 + unit_size > ctx->par_in->extradata + ctx->par_in->extradata_size) {
     100           0 :             av_log(ctx, AV_LOG_ERROR, "Packet header is not contained in global extradata, "
     101             :                    "corrupted stream or invalid MP4/AVCC bitstream\n");
     102           0 :             av_free(out);
     103           0 :             return AVERROR(EINVAL);
     104             :         }
     105          10 :         if ((err = av_reallocp(&out, total_size + padding)) < 0)
     106           0 :             return err;
     107          10 :         memcpy(out + total_size - unit_size - 4, nalu_header, 4);
     108          10 :         memcpy(out + total_size - unit_size, extradata + 2, unit_size);
     109          10 :         extradata += 2 + unit_size;
     110          10 : pps:
     111          10 :         if (!unit_nb && !sps_done++) {
     112           5 :             unit_nb = *extradata++; /* number of pps unit(s) */
     113           5 :             if (unit_nb) {
     114           5 :                 s->pps_offset = total_size;
     115           5 :                 pps_seen = 1;
     116             :             }
     117             :         }
     118             :     }
     119             : 
     120           5 :     if (out)
     121           5 :         memset(out + total_size, 0, padding);
     122             : 
     123           5 :     if (!sps_seen)
     124           0 :         av_log(ctx, AV_LOG_WARNING,
     125             :                "Warning: SPS NALU missing or invalid. "
     126             :                "The resulting stream may not play.\n");
     127             : 
     128           5 :     if (!pps_seen)
     129           0 :         av_log(ctx, AV_LOG_WARNING,
     130             :                "Warning: PPS NALU missing or invalid. "
     131             :                "The resulting stream may not play.\n");
     132             : 
     133           5 :     av_freep(&ctx->par_out->extradata);
     134           5 :     ctx->par_out->extradata      = out;
     135           5 :     ctx->par_out->extradata_size = total_size;
     136             : 
     137           5 :     return length_size;
     138             : }
     139             : 
     140           5 : static int h264_mp4toannexb_init(AVBSFContext *ctx)
     141             : {
     142           5 :     H264BSFContext *s = ctx->priv_data;
     143           5 :     int extra_size = ctx->par_in->extradata_size;
     144             :     int ret;
     145             : 
     146             :     /* retrieve sps and pps NAL units from extradata */
     147           5 :     if (!extra_size                                               ||
     148           5 :         (extra_size >= 3 && AV_RB24(ctx->par_in->extradata) == 1) ||
     149           5 :         (extra_size >= 4 && AV_RB32(ctx->par_in->extradata) == 1)) {
     150           0 :         av_log(ctx, AV_LOG_VERBOSE,
     151             :                "The input looks like it is Annex B already\n");
     152           5 :     } else if (extra_size >= 6) {
     153           5 :         ret = h264_extradata_to_annexb(ctx, AV_INPUT_BUFFER_PADDING_SIZE);
     154           5 :         if (ret < 0)
     155           0 :             return ret;
     156             : 
     157           5 :         s->length_size      = ret;
     158           5 :         s->new_idr          = 1;
     159           5 :         s->idr_sps_seen     = 0;
     160           5 :         s->idr_pps_seen     = 0;
     161           5 :         s->extradata_parsed = 1;
     162             :     } else {
     163           0 :         av_log(ctx, AV_LOG_ERROR, "Invalid extradata size: %d\n", extra_size);
     164           0 :         return AVERROR_INVALIDDATA;
     165             :     }
     166             : 
     167           5 :     return 0;
     168             : }
     169             : 
     170         530 : static int h264_mp4toannexb_filter(AVBSFContext *ctx, AVPacket *out)
     171             : {
     172         530 :     H264BSFContext *s = ctx->priv_data;
     173             : 
     174             :     AVPacket *in;
     175             :     uint8_t unit_type;
     176             :     int32_t nal_size;
     177         530 :     uint32_t cumul_size    = 0;
     178             :     const uint8_t *buf;
     179             :     const uint8_t *buf_end;
     180             :     int            buf_size;
     181         530 :     int ret = 0, i;
     182             : 
     183         530 :     ret = ff_bsf_get_packet(ctx, &in);
     184         530 :     if (ret < 0)
     185         132 :         return ret;
     186             : 
     187             :     /* nothing to filter */
     188         398 :     if (!s->extradata_parsed) {
     189           0 :         av_packet_move_ref(out, in);
     190           0 :         av_packet_free(&in);
     191           0 :         return 0;
     192             :     }
     193             : 
     194         398 :     buf      = in->data;
     195         398 :     buf_size = in->size;
     196         398 :     buf_end  = in->data + in->size;
     197             : 
     198             :     do {
     199        1741 :         ret= AVERROR(EINVAL);
     200        1741 :         if (buf + s->length_size > buf_end)
     201           0 :             goto fail;
     202             : 
     203        8705 :         for (nal_size = 0, i = 0; i<s->length_size; i++)
     204        6964 :             nal_size = (nal_size << 8) | buf[i];
     205             : 
     206        1741 :         buf += s->length_size;
     207        1741 :         unit_type = *buf & 0x1f;
     208             : 
     209        3481 :         if (nal_size > buf_end - buf || nal_size < 0)
     210             :             goto fail;
     211             : 
     212        1740 :         if (unit_type == 7)
     213           0 :             s->idr_sps_seen = s->new_idr = 1;
     214        1740 :         else if (unit_type == 8) {
     215           0 :             s->idr_pps_seen = s->new_idr = 1;
     216             :             /* if SPS has not been seen yet, prepend the AVCC one to PPS */
     217           0 :             if (!s->idr_sps_seen) {
     218           0 :                 if (s->sps_offset == -1)
     219           0 :                     av_log(ctx, AV_LOG_WARNING, "SPS not present in the stream, nor in AVCC, stream may be unreadable\n");
     220             :                 else {
     221           0 :                     if ((ret = alloc_and_copy(out,
     222           0 :                                          ctx->par_out->extradata + s->sps_offset,
     223           0 :                                          s->pps_offset != -1 ? s->pps_offset : ctx->par_out->extradata_size - s->sps_offset,
     224             :                                          buf, nal_size)) < 0)
     225           0 :                         goto fail;
     226           0 :                     s->idr_sps_seen = 1;
     227           0 :                     goto next_nal;
     228             :                 }
     229             :             }
     230             :         }
     231             : 
     232             :         /* if this is a new IDR picture following an IDR picture, reset the idr flag.
     233             :          * Just check first_mb_in_slice to be 0 as this is the simplest solution.
     234             :          * This could be checking idr_pic_id instead, but would complexify the parsing. */
     235        1740 :         if (!s->new_idr && unit_type == 5 && (buf[1] & 0x80))
     236           0 :             s->new_idr = 1;
     237             : 
     238             :         /* prepend only to the first type 5 NAL unit of an IDR picture, if no sps/pps are already present */
     239        1740 :         if (s->new_idr && unit_type == 5 && !s->idr_sps_seen && !s->idr_pps_seen) {
     240          42 :             if ((ret=alloc_and_copy(out,
     241          28 :                                ctx->par_out->extradata, ctx->par_out->extradata_size,
     242             :                                buf, nal_size)) < 0)
     243           0 :                 goto fail;
     244          14 :             s->new_idr = 0;
     245             :         /* if only SPS has been seen, also insert PPS */
     246        1726 :         } else if (s->new_idr && unit_type == 5 && s->idr_sps_seen && !s->idr_pps_seen) {
     247           0 :             if (s->pps_offset == -1) {
     248           0 :                 av_log(ctx, AV_LOG_WARNING, "PPS not present in the stream, nor in AVCC, stream may be unreadable\n");
     249           0 :                 if ((ret = alloc_and_copy(out, NULL, 0, buf, nal_size)) < 0)
     250           0 :                     goto fail;
     251           0 :             } else if ((ret = alloc_and_copy(out,
     252           0 :                                         ctx->par_out->extradata + s->pps_offset, ctx->par_out->extradata_size - s->pps_offset,
     253             :                                         buf, nal_size)) < 0)
     254           0 :                 goto fail;
     255             :         } else {
     256        1726 :             if ((ret=alloc_and_copy(out, NULL, 0, buf, nal_size)) < 0)
     257           0 :                 goto fail;
     258        1812 :             if (!s->new_idr && unit_type == 1) {
     259          12 :                 s->new_idr = 1;
     260          12 :                 s->idr_sps_seen = 0;
     261          12 :                 s->idr_pps_seen = 0;
     262             :             }
     263             :         }
     264             : 
     265        3454 : next_nal:
     266        1740 :         buf        += nal_size;
     267        1740 :         cumul_size += nal_size + s->length_size;
     268        1740 :     } while (cumul_size < buf_size);
     269             : 
     270         397 :     ret = av_packet_copy_props(out, in);
     271         397 :     if (ret < 0)
     272           0 :         goto fail;
     273             : 
     274         796 : fail:
     275         398 :     if (ret < 0)
     276           1 :         av_packet_unref(out);
     277         398 :     av_packet_free(&in);
     278             : 
     279         398 :     return ret;
     280             : }
     281             : 
     282             : static const enum AVCodecID codec_ids[] = {
     283             :     AV_CODEC_ID_H264, AV_CODEC_ID_NONE,
     284             : };
     285             : 
     286             : const AVBitStreamFilter ff_h264_mp4toannexb_bsf = {
     287             :     .name           = "h264_mp4toannexb",
     288             :     .priv_data_size = sizeof(H264BSFContext),
     289             :     .init           = h264_mp4toannexb_init,
     290             :     .filter         = h264_mp4toannexb_filter,
     291             :     .codec_ids      = codec_ids,
     292             : };

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