FFmpeg: libavformat/rtpenc_aac.c Source File

FFmpeg

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libavformat

rtpenc_aac.c

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1 /*

3 *

4 * This file is part of FFmpeg.

5 *

6 * FFmpeg is free software; you can redistribute it and/or

7 * modify it under the terms of the GNU Lesser General Public

8 * License as published by the Free Software Foundation; either

9 * version 2.1 of the License, or (at your option) any later version.

10 *

11 * FFmpeg is distributed in the hope that it will be useful,

12 * but WITHOUT ANY WARRANTY; without even the implied warranty of

13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

14 * Lesser General Public License for more details.

15 *

16 * You should have received a copy of the GNU Lesser General Public

17 * License along with FFmpeg; if not, write to the Free Software

18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

19 */

21 #include "avformat.h"

22 #include "rtpenc.h"

25 void ff_rtp_send_aac(AVFormatContext *s1, const uint8_t *buff, int size)

26 {

27 RTPMuxContext *s = s1->priv_data;

28 int len, max_packet_size;

29 uint8_t *p;

30 const int max_frames_per_packet = s->max_frames_per_packet ? s->max_frames_per_packet : 5;

31 const int max_au_headers_size = 2 + 2 * max_frames_per_packet;

33 /* skip ADTS header, if present */

34 if ((s1->streams[0]->codec->extradata_size) == 0) {

35 size -= 7;

36 buff += 7;

37 }

38 max_packet_size = s->max_payload_size - max_au_headers_size;

40 /* test if the packet must be sent */

41 len = (s->buf_ptr - s->buf);

42 if ((s->num_frames == max_frames_per_packet) || (len && (len + size) > s->max_payload_size)) {

43 int au_size = s->num_frames * 2;

45 p = s->buf + max_au_headers_size - au_size - 2;

46 if (p != s->buf) {

47 memmove(p + 2, s->buf + 2, au_size);

48 }

49 /* Write the AU header size */

50 p[0] = au_size >> 5;

51 p[1] = (au_size & 0x1F) << 3;

53 ff_rtp_send_data(s1, p, s->buf_ptr - p, 1);

55 s->num_frames = 0;

56 }

57 if (s->num_frames == 0) {

58 s->buf_ptr = s->buf + max_au_headers_size;

59 s->timestamp = s->cur_timestamp;

60 }

62 if (size <= max_packet_size) {

63 p = s->buf + s->num_frames++ * 2 + 2;

64 *p++ = size >> 5;

65 *p = (size & 0x1F) << 3;

66 memcpy(s->buf_ptr, buff, size);

67 s->buf_ptr += size;

68 } else {

69 int au_size = size;

71 max_packet_size = s->max_payload_size - 4;

72 p = s->buf;

73 p[0] = 0;

74 p[1] = 16;

75 while (size > 0) {

76 len = FFMIN(size, max_packet_size);

77 p[2] = au_size >> 5;

78 p[3] = (au_size & 0x1F) << 3;

79 memcpy(p + 4, buff, len);

80 ff_rtp_send_data(s1, p, len + 4, len == size);

81 size -= len;

82 buff += len;

83 }

84 }

85 }

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