| /* |
| * H.264 MP4 to Annex B byte stream format filter |
| * Copyright (c) 2007 Benoit Fouet <benoit.fouet@free.fr> |
| * |
| * 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 <string.h> |
| |
| #include "libavutil/intreadwrite.h" |
| #include "libavutil/mem.h" |
| #include "avcodec.h" |
| |
| typedef struct H264BSFContext { |
| uint8_t length_size; |
| uint8_t first_idr; |
| uint8_t idr_sps_pps_seen; |
| int extradata_parsed; |
| } H264BSFContext; |
| |
| static int alloc_and_copy(uint8_t **poutbuf, int *poutbuf_size, |
| const uint8_t *sps_pps, uint32_t sps_pps_size, |
| const uint8_t *in, uint32_t in_size) |
| { |
| uint32_t offset = *poutbuf_size; |
| uint8_t nal_header_size = offset ? 3 : 4; |
| int err; |
| |
| *poutbuf_size += sps_pps_size + in_size + nal_header_size; |
| if ((err = av_reallocp(poutbuf, |
| *poutbuf_size + FF_INPUT_BUFFER_PADDING_SIZE)) < 0) { |
| *poutbuf_size = 0; |
| return err; |
| } |
| if (sps_pps) |
| memcpy(*poutbuf + offset, sps_pps, sps_pps_size); |
| memcpy(*poutbuf + sps_pps_size + nal_header_size + offset, in, in_size); |
| if (!offset) { |
| AV_WB32(*poutbuf + sps_pps_size, 1); |
| } else { |
| (*poutbuf + offset + sps_pps_size)[0] = |
| (*poutbuf + offset + sps_pps_size)[1] = 0; |
| (*poutbuf + offset + sps_pps_size)[2] = 1; |
| } |
| |
| return 0; |
| } |
| |
| static int h264_extradata_to_annexb(AVCodecContext *avctx, const int padding) |
| { |
| uint16_t unit_size; |
| uint64_t total_size = 0; |
| uint8_t *out = NULL, unit_nb, sps_done = 0, |
| sps_seen = 0, pps_seen = 0; |
| const uint8_t *extradata = avctx->extradata + 4; |
| static const uint8_t nalu_header[4] = { 0, 0, 0, 1 }; |
| int length_size = (*extradata++ & 0x3) + 1; // retrieve length coded size |
| |
| /* retrieve sps and pps unit(s) */ |
| unit_nb = *extradata++ & 0x1f; /* number of sps unit(s) */ |
| if (!unit_nb) { |
| goto pps; |
| } else { |
| sps_seen = 1; |
| } |
| |
| while (unit_nb--) { |
| int err; |
| |
| unit_size = AV_RB16(extradata); |
| total_size += unit_size + 4; |
| if (total_size > INT_MAX - padding) { |
| av_log(avctx, AV_LOG_ERROR, |
| "Too big extradata size, corrupted stream or invalid MP4/AVCC bitstream\n"); |
| av_free(out); |
| return AVERROR(EINVAL); |
| } |
| if (extradata + 2 + unit_size > avctx->extradata + avctx->extradata_size) { |
| av_log(avctx, AV_LOG_ERROR, "Packet header is not contained in global extradata, " |
| "corrupted stream or invalid MP4/AVCC bitstream\n"); |
| av_free(out); |
| return AVERROR(EINVAL); |
| } |
| if ((err = av_reallocp(&out, total_size + padding)) < 0) |
| return err; |
| memcpy(out + total_size - unit_size - 4, nalu_header, 4); |
| memcpy(out + total_size - unit_size, extradata + 2, unit_size); |
| extradata += 2 + unit_size; |
| pps: |
| if (!unit_nb && !sps_done++) { |
| unit_nb = *extradata++; /* number of pps unit(s) */ |
| if (unit_nb) |
| pps_seen = 1; |
| } |
| } |
| |
| if (out) |
| memset(out + total_size, 0, FF_INPUT_BUFFER_PADDING_SIZE); |
| |
| if (!sps_seen) |
| av_log(avctx, AV_LOG_WARNING, |
| "Warning: SPS NALU missing or invalid. " |
| "The resulting stream may not play.\n"); |
| |
| if (!pps_seen) |
| av_log(avctx, AV_LOG_WARNING, |
| "Warning: PPS NALU missing or invalid. " |
| "The resulting stream may not play.\n"); |
| |
| av_free(avctx->extradata); |
| avctx->extradata = out; |
| avctx->extradata_size = total_size; |
| |
| return length_size; |
| } |
| |
| static int h264_mp4toannexb_filter(AVBitStreamFilterContext *bsfc, |
| AVCodecContext *avctx, const char *args, |
| uint8_t **poutbuf, int *poutbuf_size, |
| const uint8_t *buf, int buf_size, |
| int keyframe) |
| { |
| H264BSFContext *ctx = bsfc->priv_data; |
| int i; |
| uint8_t unit_type; |
| int32_t nal_size; |
| uint32_t cumul_size = 0; |
| const uint8_t *buf_end = buf + buf_size; |
| int ret = 0; |
| |
| /* nothing to filter */ |
| if (!avctx->extradata || avctx->extradata_size < 6) { |
| *poutbuf = (uint8_t *)buf; |
| *poutbuf_size = buf_size; |
| return 0; |
| } |
| |
| /* retrieve sps and pps NAL units from extradata */ |
| if (!ctx->extradata_parsed) { |
| ret = h264_extradata_to_annexb(avctx, FF_INPUT_BUFFER_PADDING_SIZE); |
| if (ret < 0) |
| return ret; |
| ctx->length_size = ret; |
| ctx->first_idr = 1; |
| ctx->idr_sps_pps_seen = 0; |
| ctx->extradata_parsed = 1; |
| } |
| |
| *poutbuf_size = 0; |
| *poutbuf = NULL; |
| do { |
| ret= AVERROR(EINVAL); |
| if (buf + ctx->length_size > buf_end) |
| goto fail; |
| |
| for (nal_size = 0, i = 0; i<ctx->length_size; i++) |
| nal_size = (nal_size << 8) | buf[i]; |
| |
| buf += ctx->length_size; |
| unit_type = *buf & 0x1f; |
| |
| if (buf + nal_size > buf_end || nal_size < 0) |
| goto fail; |
| |
| if (ctx->first_idr && (unit_type == 7 || unit_type == 8)) |
| ctx->idr_sps_pps_seen = 1; |
| |
| /* if this is a new IDR picture following an IDR picture, reset the idr flag. |
| * Just check first_mb_in_slice to be 0 as this is the simplest solution. |
| * This could be checking idr_pic_id instead, but would complexify the parsing. */ |
| if (!ctx->first_idr && unit_type == 5 && (buf[1] & 0x80)) |
| ctx->first_idr = 1; |
| |
| /* prepend only to the first type 5 NAL unit of an IDR picture, if no sps/pps are already present */ |
| if (ctx->first_idr && unit_type == 5 && !ctx->idr_sps_pps_seen) { |
| if ((ret=alloc_and_copy(poutbuf, poutbuf_size, |
| avctx->extradata, avctx->extradata_size, |
| buf, nal_size)) < 0) |
| goto fail; |
| ctx->first_idr = 0; |
| } else { |
| if ((ret=alloc_and_copy(poutbuf, poutbuf_size, |
| NULL, 0, buf, nal_size)) < 0) |
| goto fail; |
| if (!ctx->first_idr && unit_type == 1) { |
| ctx->first_idr = 1; |
| ctx->idr_sps_pps_seen = 0; |
| } |
| } |
| |
| buf += nal_size; |
| cumul_size += nal_size + ctx->length_size; |
| } while (cumul_size < buf_size); |
| |
| return 1; |
| |
| fail: |
| av_freep(poutbuf); |
| *poutbuf_size = 0; |
| return ret; |
| } |
| |
| AVBitStreamFilter ff_h264_mp4toannexb_bsf = { |
| .name = "h264_mp4toannexb", |
| .priv_data_size = sizeof(H264BSFContext), |
| .filter = h264_mp4toannexb_filter, |
| }; |
