yading@11: /*
yading@11:  * AVC helper functions for muxers
yading@11:  * Copyright (c) 2006 Baptiste Coudurier <baptiste.coudurier@smartjog.com>
yading@11:  *
yading@11:  * This file is part of FFmpeg.
yading@11:  *
yading@11:  * FFmpeg is free software; you can redistribute it and/or
yading@11:  * modify it under the terms of the GNU Lesser General Public
yading@11:  * License as published by the Free Software Foundation; either
yading@11:  * version 2.1 of the License, or (at your option) any later version.
yading@11:  *
yading@11:  * FFmpeg is distributed in the hope that it will be useful,
yading@11:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@11:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@11:  * Lesser General Public License for more details.
yading@11:  *
yading@11:  * You should have received a copy of the GNU Lesser General Public
yading@11:  * License along with FFmpeg; if not, write to the Free Software
yading@11:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@11:  */
yading@11: 
yading@11: #include "libavutil/intreadwrite.h"
yading@11: #include "avformat.h"
yading@11: #include "avio.h"
yading@11: #include "avc.h"
yading@11: 
yading@11: static const uint8_t *ff_avc_find_startcode_internal(const uint8_t *p, const uint8_t *end)
yading@11: {
yading@11:     const uint8_t *a = p + 4 - ((intptr_t)p & 3);
yading@11: 
yading@11:     for (end -= 3; p < a && p < end; p++) {
yading@11:         if (p[0] == 0 && p[1] == 0 && p[2] == 1)
yading@11:             return p;
yading@11:     }
yading@11: 
yading@11:     for (end -= 3; p < end; p += 4) {
yading@11:         uint32_t x = *(const uint32_t*)p;
yading@11: //      if ((x - 0x01000100) & (~x) & 0x80008000) // little endian
yading@11: //      if ((x - 0x00010001) & (~x) & 0x00800080) // big endian
yading@11:         if ((x - 0x01010101) & (~x) & 0x80808080) { // generic
yading@11:             if (p[1] == 0) {
yading@11:                 if (p[0] == 0 && p[2] == 1)
yading@11:                     return p;
yading@11:                 if (p[2] == 0 && p[3] == 1)
yading@11:                     return p+1;
yading@11:             }
yading@11:             if (p[3] == 0) {
yading@11:                 if (p[2] == 0 && p[4] == 1)
yading@11:                     return p+2;
yading@11:                 if (p[4] == 0 && p[5] == 1)
yading@11:                     return p+3;
yading@11:             }
yading@11:         }
yading@11:     }
yading@11: 
yading@11:     for (end += 3; p < end; p++) {
yading@11:         if (p[0] == 0 && p[1] == 0 && p[2] == 1)
yading@11:             return p;
yading@11:     }
yading@11: 
yading@11:     return end + 3;
yading@11: }
yading@11: 
yading@11: const uint8_t *ff_avc_find_startcode(const uint8_t *p, const uint8_t *end){
yading@11:     const uint8_t *out= ff_avc_find_startcode_internal(p, end);
yading@11:     if(p<out && out<end && !out[-1]) out--;
yading@11:     return out;
yading@11: }
yading@11: 
yading@11: int ff_avc_parse_nal_units(AVIOContext *pb, const uint8_t *buf_in, int size)
yading@11: {
yading@11:     const uint8_t *p = buf_in;
yading@11:     const uint8_t *end = p + size;
yading@11:     const uint8_t *nal_start, *nal_end;
yading@11: 
yading@11:     size = 0;
yading@11:     nal_start = ff_avc_find_startcode(p, end);
yading@11:     for (;;) {
yading@11:         while (nal_start < end && !*(nal_start++));
yading@11:         if (nal_start == end)
yading@11:             break;
yading@11: 
yading@11:         nal_end = ff_avc_find_startcode(nal_start, end);
yading@11:         avio_wb32(pb, nal_end - nal_start);
yading@11:         avio_write(pb, nal_start, nal_end - nal_start);
yading@11:         size += 4 + nal_end - nal_start;
yading@11:         nal_start = nal_end;
yading@11:     }
yading@11:     return size;
yading@11: }
yading@11: 
yading@11: int ff_avc_parse_nal_units_buf(const uint8_t *buf_in, uint8_t **buf, int *size)
yading@11: {
yading@11:     AVIOContext *pb;
yading@11:     int ret = avio_open_dyn_buf(&pb);
yading@11:     if(ret < 0)
yading@11:         return ret;
yading@11: 
yading@11:     ff_avc_parse_nal_units(pb, buf_in, *size);
yading@11: 
yading@11:     av_freep(buf);
yading@11:     *size = avio_close_dyn_buf(pb, buf);
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: int ff_isom_write_avcc(AVIOContext *pb, const uint8_t *data, int len)
yading@11: {
yading@11:     if (len > 6) {
yading@11:         /* check for h264 start code */
yading@11:         if (AV_RB32(data) == 0x00000001 ||
yading@11:             AV_RB24(data) == 0x000001) {
yading@11:             uint8_t *buf=NULL, *end, *start;
yading@11:             uint32_t sps_size=0, pps_size=0;
yading@11:             uint8_t *sps=0, *pps=0;
yading@11: 
yading@11:             int ret = ff_avc_parse_nal_units_buf(data, &buf, &len);
yading@11:             if (ret < 0)
yading@11:                 return ret;
yading@11:             start = buf;
yading@11:             end = buf + len;
yading@11: 
yading@11:             /* look for sps and pps */
yading@11:             while (end - buf > 4) {
yading@11:                 uint32_t size;
yading@11:                 uint8_t nal_type;
yading@11:                 size = FFMIN(AV_RB32(buf), end - buf - 4);
yading@11:                 buf += 4;
yading@11:                 nal_type = buf[0] & 0x1f;
yading@11: 
yading@11:                 if (nal_type == 7) { /* SPS */
yading@11:                     sps = buf;
yading@11:                     sps_size = size;
yading@11:                 } else if (nal_type == 8) { /* PPS */
yading@11:                     pps = buf;
yading@11:                     pps_size = size;
yading@11:                 }
yading@11: 
yading@11:                 buf += size;
yading@11:             }
yading@11: 
yading@11:             if (!sps || !pps || sps_size < 4 || sps_size > UINT16_MAX || pps_size > UINT16_MAX)
yading@11:                 return AVERROR_INVALIDDATA;
yading@11: 
yading@11:             avio_w8(pb, 1); /* version */
yading@11:             avio_w8(pb, sps[1]); /* profile */
yading@11:             avio_w8(pb, sps[2]); /* profile compat */
yading@11:             avio_w8(pb, sps[3]); /* level */
yading@11:             avio_w8(pb, 0xff); /* 6 bits reserved (111111) + 2 bits nal size length - 1 (11) */
yading@11:             avio_w8(pb, 0xe1); /* 3 bits reserved (111) + 5 bits number of sps (00001) */
yading@11: 
yading@11:             avio_wb16(pb, sps_size);
yading@11:             avio_write(pb, sps, sps_size);
yading@11:             avio_w8(pb, 1); /* number of pps */
yading@11:             avio_wb16(pb, pps_size);
yading@11:             avio_write(pb, pps, pps_size);
yading@11:             av_free(start);
yading@11:         } else {
yading@11:             avio_write(pb, data, len);
yading@11:         }
yading@11:     }
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: int ff_avc_write_annexb_extradata(const uint8_t *in, uint8_t **buf, int *size)
yading@11: {
yading@11:     uint16_t sps_size, pps_size;
yading@11:     uint8_t *out;
yading@11:     int out_size;
yading@11: 
yading@11:     *buf = NULL;
yading@11:     if (*size >= 4 && (AV_RB32(in) == 0x00000001 || AV_RB24(in) == 0x000001))
yading@11:         return 0;
yading@11:     if (*size < 11 || in[0] != 1)
yading@11:         return AVERROR_INVALIDDATA;
yading@11: 
yading@11:     sps_size = AV_RB16(&in[6]);
yading@11:     if (11 + sps_size > *size)
yading@11:         return AVERROR_INVALIDDATA;
yading@11:     pps_size = AV_RB16(&in[9 + sps_size]);
yading@11:     if (11 + sps_size + pps_size > *size)
yading@11:         return AVERROR_INVALIDDATA;
yading@11:     out_size = 8 + sps_size + pps_size;
yading@11:     out = av_mallocz(out_size);
yading@11:     if (!out)
yading@11:         return AVERROR(ENOMEM);
yading@11:     AV_WB32(&out[0], 0x00000001);
yading@11:     memcpy(out + 4, &in[8], sps_size);
yading@11:     AV_WB32(&out[4 + sps_size], 0x00000001);
yading@11:     memcpy(out + 8 + sps_size, &in[11 + sps_size], pps_size);
yading@11:     *buf = out;
yading@11:     *size = out_size;
yading@11:     return 0;
yading@11: }