FFmpeg: libavcodec/adts_parser.c Source File

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libavcodec

adts_parser.c

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1 /*

2 * This file is part of FFmpeg.

3 *

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

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

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

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

8 *

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

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

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

12 * Lesser General Public License for more details.

13 *

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

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

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

17 */

19 #include "config.h"

21 #include <stddef.h>

22 #include <stdint.h>

24 #include "adts_header.h"

25 #include "adts_parser.h"

27 int av_adts_header_parse(const uint8_t *buf, uint32_t *samples, uint8_t *frames)

28 {

29 #if CONFIG_ADTS_HEADER

30 GetBitContext gb;

31 AACADTSHeaderInfo hdr;

32 int err = init_get_bits8(&gb, buf, AV_AAC_ADTS_HEADER_SIZE);

33 if (err < 0)

34 return err;

35 err = ff_adts_header_parse(&gb, &hdr);

36 if (err < 0)

37 return err;

38 *samples = hdr.samples;

39 *frames = hdr.num_aac_frames;

40 return 0;

41 #else

42 return AVERROR(ENOSYS);

43 #endif

44 }

46 int avpriv_adts_header_parse(AACADTSHeaderInfo **phdr, const uint8_t *buf, size_t size)

47 {

48 #if CONFIG_ADTS_HEADER

49 int ret = 0;

50 int allocated = 0;

51 GetBitContext gb;

53 if (!phdr || !buf || size < AV_AAC_ADTS_HEADER_SIZE)

54 return AVERROR_INVALIDDATA;

56 if (!*phdr) {

57 allocated = 1;

58 *phdr = av_mallocz(sizeof(AACADTSHeaderInfo));

59 }

60 if (!*phdr)

61 return AVERROR(ENOMEM);

63 ret = init_get_bits8(&gb, buf, AV_AAC_ADTS_HEADER_SIZE);

64 if (ret < 0) {

65 if (allocated)

66 av_freep(phdr);

67 return ret;

68 }

70 ret = ff_adts_header_parse(&gb, *phdr);

71 if (ret < 0) {

72 if (allocated)

73 av_freep(phdr);

74 return ret;

75 }

77 return 0;

78 #else

79 return AVERROR(ENOSYS);

80 #endif

81 }

AVERROR

Filter the word "frame" indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions

AV_AAC_ADTS_HEADER_SIZE

#define AV_AAC_ADTS_HEADER_SIZE

Definition: adts_parser.h:25

AACADTSHeaderInfo::samples

uint32_t samples

Definition: adts_header.h:30

av_adts_header_parse

int av_adts_header_parse(const uint8_t *buf, uint32_t *samples, uint8_t *frames)

Extract the number of samples and frames from AAC data.

Definition: adts_parser.c:27

ff_adts_header_parse

int ff_adts_header_parse(GetBitContext *gbc, AACADTSHeaderInfo *hdr)