FFmpeg: libswresample/swresample_frame.c Source File

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libswresample

swresample_frame.c

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1 /*

4 *

5 * This file is part of FFmpeg.

6 *

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

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

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

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

11 *

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

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

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

15 * Lesser General Public License for more details.

16 *

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

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

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

20 */

22 #include "swresample_internal.h"

23 #include "libavutil/frame.h"

24 #include "libavutil/opt.h"

26 int swr_config_frame(SwrContext *s, const AVFrame *out, const AVFrame *in)

27 {

28 swr_close(s);

30 if (in) {

31 if (av_opt_set_int(s, "icl", in->channel_layout, 0) < 0)

32 goto fail;

33 if (av_opt_set_int(s, "isf", in->format, 0) < 0)

34 goto fail;

35 if (av_opt_set_int(s, "isr", in->sample_rate, 0) < 0)

36 goto fail;

37 }

39 if (out) {

40 if (av_opt_set_int(s, "ocl", out->channel_layout, 0) < 0)

41 goto fail;

42 if (av_opt_set_int(s, "osf", out->format, 0) < 0)

43 goto fail;

44 if (av_opt_set_int(s, "osr", out->sample_rate, 0) < 0)

45 goto fail;

46 }

48 return 0;

49 fail:

50 av_log(s, AV_LOG_ERROR, "Failed to set option\n");

51 return AVERROR(EINVAL);

52 }

54 static int config_changed(SwrContext *s,

55 const AVFrame *out, const AVFrame *in)

56 {

57 int ret = 0;

59 if (in) {

60 if (s->in_ch_layout != in->channel_layout ||

61 s->in_sample_rate != in->sample_rate ||

62 s->in_sample_fmt != in->format) {

63 ret |= AVERROR_INPUT_CHANGED;

64 }

65 }

67 if (out) {

68 if (s->out_ch_layout != out->channel_layout ||

69 s->out_sample_rate != out->sample_rate ||

70 s->out_sample_fmt != out->format) {

71 ret |= AVERROR_OUTPUT_CHANGED;

72 }

73 }

75 return ret;

76 }

78 static inline int convert_frame(SwrContext *s,

79 AVFrame *out, const AVFrame *in)

80 {

81 int ret;

82 uint8_t **out_data = NULL;

83 const uint8_t **in_data = NULL;

84 int out_nb_samples = 0, in_nb_samples = 0;

86 if (out) {

87 out_data = out->extended_data;

88 out_nb_samples = out->nb_samples;

89 }

91 if (in) {

92 in_data = (const uint8_t **)in->extended_data;

93 in_nb_samples = in->nb_samples;

94 }

96 ret = swr_convert(s, out_data, out_nb_samples, in_data, in_nb_samples);

98 if (ret < 0) {

99 if (out)

100 out->nb_samples = 0;

101 return ret;

102 }

103

104 if (out)

105 out->nb_samples = ret;

106

107 return 0;

108 }

109

110 static inline int available_samples(AVFrame *out)

111 {

112 int bytes_per_sample = av_get_bytes_per_sample(out->format);

113 int samples = out->linesize[0] / bytes_per_sample;

114

115 if (av_sample_fmt_is_planar(out->format)) {

116 return samples;

117 } else {

118 int channels = av_get_channel_layout_nb_channels(out->channel_layout);

119 return samples / channels;

120 }

121 }

122

123 int swr_convert_frame(SwrContext *s,

124 AVFrame *out, const AVFrame *in)

125 {

126 int ret, setup = 0;

127

128 if (!swr_is_initialized(s)) {

129 if ((ret = swr_config_frame(s, out, in)) < 0)

130 return ret;

131 if ((ret = swr_init(s)) < 0)

132 return ret;

133 setup = 1;

134 } else {

135 // return as is or reconfigure for input changes?

136 if ((ret = config_changed(s, out, in)))

137 return ret;

138 }

139

140 if (out) {

141 if (!out->linesize[0]) {

142 out->nb_samples = swr_get_delay(s, s->out_sample_rate)

143 + in->nb_samples*(int64_t)s->out_sample_rate / s->in_sample_rate

144 + 3;

145 if ((ret = av_frame_get_buffer(out, 0)) < 0) {

146 if (setup)

147 swr_close(s);

148 return ret;

149 }

150 } else {

151 if (!out->nb_samples)

152 out->nb_samples = available_samples(out);

153 }

154 }

155

156 return convert_frame(s, out, in);

157 }

158

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