diff options
Diffstat (limited to 'ffmpeg/libavformat/avc.c')
| -rw-r--r-- | ffmpeg/libavformat/avc.c | 193 |
1 files changed, 193 insertions, 0 deletions
diff --git a/ffmpeg/libavformat/avc.c b/ffmpeg/libavformat/avc.c new file mode 100644 index 0000000..f5c513b --- /dev/null +++ b/ffmpeg/libavformat/avc.c @@ -0,0 +1,193 @@ +/* + * AVC helper functions for muxers + * Copyright (c) 2006 Baptiste Coudurier <baptiste.coudurier@smartjog.com> + * + * 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 "libavutil/intreadwrite.h" +#include "avformat.h" +#include "avio.h" +#include "avc.h" + +static const uint8_t *ff_avc_find_startcode_internal(const uint8_t *p, const uint8_t *end) +{ + const uint8_t *a = p + 4 - ((intptr_t)p & 3); + + for (end -= 3; p < a && p < end; p++) { + if (p[0] == 0 && p[1] == 0 && p[2] == 1) + return p; + } + + for (end -= 3; p < end; p += 4) { + uint32_t x = *(const uint32_t*)p; +// if ((x - 0x01000100) & (~x) & 0x80008000) // little endian +// if ((x - 0x00010001) & (~x) & 0x00800080) // big endian + if ((x - 0x01010101) & (~x) & 0x80808080) { // generic + if (p[1] == 0) { + if (p[0] == 0 && p[2] == 1) + return p; + if (p[2] == 0 && p[3] == 1) + return p+1; + } + if (p[3] == 0) { + if (p[2] == 0 && p[4] == 1) + return p+2; + if (p[4] == 0 && p[5] == 1) + return p+3; + } + } + } + + for (end += 3; p < end; p++) { + if (p[0] == 0 && p[1] == 0 && p[2] == 1) + return p; + } + + return end + 3; +} + +const uint8_t *ff_avc_find_startcode(const uint8_t *p, const uint8_t *end){ + const uint8_t *out= ff_avc_find_startcode_internal(p, end); + if(p<out && out<end && !out[-1]) out--; + return out; +} + +int ff_avc_parse_nal_units(AVIOContext *pb, const uint8_t *buf_in, int size) +{ + const uint8_t *p = buf_in; + const uint8_t *end = p + size; + const uint8_t *nal_start, *nal_end; + + size = 0; + nal_start = ff_avc_find_startcode(p, end); + for (;;) { + while (nal_start < end && !*(nal_start++)); + if (nal_start == end) + break; + + nal_end = ff_avc_find_startcode(nal_start, end); + avio_wb32(pb, nal_end - nal_start); + avio_write(pb, nal_start, nal_end - nal_start); + size += 4 + nal_end - nal_start; + nal_start = nal_end; + } + return size; +} + +int ff_avc_parse_nal_units_buf(const uint8_t *buf_in, uint8_t **buf, int *size) +{ + AVIOContext *pb; + int ret = avio_open_dyn_buf(&pb); + if(ret < 0) + return ret; + + ff_avc_parse_nal_units(pb, buf_in, *size); + + av_freep(buf); + *size = avio_close_dyn_buf(pb, buf); + return 0; +} + +int ff_isom_write_avcc(AVIOContext *pb, const uint8_t *data, int len) +{ + if (len > 6) { + /* check for h264 start code */ + if (AV_RB32(data) == 0x00000001 || + AV_RB24(data) == 0x000001) { + uint8_t *buf=NULL, *end, *start; + uint32_t sps_size=0, pps_size=0; + uint8_t *sps=0, *pps=0; + + int ret = ff_avc_parse_nal_units_buf(data, &buf, &len); + if (ret < 0) + return ret; + start = buf; + end = buf + len; + + /* look for sps and pps */ + while (end - buf > 4) { + uint32_t size; + uint8_t nal_type; + size = FFMIN(AV_RB32(buf), end - buf - 4); + buf += 4; + nal_type = buf[0] & 0x1f; + + if (nal_type == 7) { /* SPS */ + sps = buf; + sps_size = size; + } else if (nal_type == 8) { /* PPS */ + pps = buf; + pps_size = size; + } + + buf += size; + } + + if (!sps || !pps || sps_size < 4 || sps_size > UINT16_MAX || pps_size > UINT16_MAX) + return AVERROR_INVALIDDATA; + + avio_w8(pb, 1); /* version */ + avio_w8(pb, sps[1]); /* profile */ + avio_w8(pb, sps[2]); /* profile compat */ + avio_w8(pb, sps[3]); /* level */ + avio_w8(pb, 0xff); /* 6 bits reserved (111111) + 2 bits nal size length - 1 (11) */ + avio_w8(pb, 0xe1); /* 3 bits reserved (111) + 5 bits number of sps (00001) */ + + avio_wb16(pb, sps_size); + avio_write(pb, sps, sps_size); + avio_w8(pb, 1); /* number of pps */ + avio_wb16(pb, pps_size); + avio_write(pb, pps, pps_size); + av_free(start); + } else { + avio_write(pb, data, len); + } + } + return 0; +} + +int ff_avc_write_annexb_extradata(const uint8_t *in, uint8_t **buf, int *size) +{ + uint16_t sps_size, pps_size; + uint8_t *out; + int out_size; + + *buf = NULL; + if (*size >= 4 && (AV_RB32(in) == 0x00000001 || AV_RB24(in) == 0x000001)) + return 0; + if (*size < 11 || in[0] != 1) + return AVERROR_INVALIDDATA; + + sps_size = AV_RB16(&in[6]); + if (11 + sps_size > *size) + return AVERROR_INVALIDDATA; + pps_size = AV_RB16(&in[9 + sps_size]); + if (11 + sps_size + pps_size > *size) + return AVERROR_INVALIDDATA; + out_size = 8 + sps_size + pps_size; + out = av_mallocz(out_size); + if (!out) + return AVERROR(ENOMEM); + AV_WB32(&out[0], 0x00000001); + memcpy(out + 4, &in[8], sps_size); + AV_WB32(&out[4 + sps_size], 0x00000001); + memcpy(out + 8 + sps_size, &in[11 + sps_size], pps_size); + *buf = out; + *size = out_size; + return 0; +} |