2 * This file is part of FFmpeg.
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.
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.
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
19 #include "libavutil/avstring.h"
20 #include "libavutil/common.h"
21 #include "libavutil/opt.h"
25 #include "cbs_mpeg2.h"
28 typedef struct MPEG2MetadataContext {
31 CodedBitstreamContext *cbc;
32 CodedBitstreamFragment fragment;
34 MPEG2RawExtensionData sequence_display_extension;
36 AVRational display_aspect_ratio;
38 AVRational frame_rate;
42 int transfer_characteristics;
43 int matrix_coefficients;
46 } MPEG2MetadataContext;
49 static int mpeg2_metadata_update_fragment(AVBSFContext *bsf,
50 CodedBitstreamFragment *frag)
52 MPEG2MetadataContext *ctx = bsf->priv_data;
53 MPEG2RawSequenceHeader *sh = NULL;
54 MPEG2RawSequenceExtension *se = NULL;
55 MPEG2RawSequenceDisplayExtension *sde = NULL;
58 for (i = 0; i < frag->nb_units; i++) {
59 if (frag->units[i].type == MPEG2_START_SEQUENCE_HEADER) {
60 sh = frag->units[i].content;
61 } else if (frag->units[i].type == MPEG2_START_EXTENSION) {
62 MPEG2RawExtensionData *ext = frag->units[i].content;
63 if (ext->extension_start_code_identifier ==
64 MPEG2_EXTENSION_SEQUENCE) {
65 se = &ext->data.sequence;
67 } else if (ext->extension_start_code_identifier ==
68 MPEG2_EXTENSION_SEQUENCE_DISPLAY) {
69 sde = &ext->data.sequence_display;
75 // No sequence header and sequence extension: not an MPEG-2 video
77 if (sh && !ctx->mpeg1_warned) {
78 av_log(bsf, AV_LOG_WARNING, "Stream contains a sequence "
79 "header but not a sequence extension: maybe it's "
80 "actually MPEG-1?\n");
81 ctx->mpeg1_warned = 1;
86 if (ctx->display_aspect_ratio.num && ctx->display_aspect_ratio.den) {
89 av_reduce(&num, &den, ctx->display_aspect_ratio.num,
90 ctx->display_aspect_ratio.den, 65535);
92 if (num == 4 && den == 3)
93 sh->aspect_ratio_information = 2;
94 else if (num == 16 && den == 9)
95 sh->aspect_ratio_information = 3;
96 else if (num == 221 && den == 100)
97 sh->aspect_ratio_information = 4;
99 sh->aspect_ratio_information = 1;
102 if (ctx->frame_rate.num && ctx->frame_rate.den) {
103 int code, ext_n, ext_d;
105 ff_mpeg12_find_best_frame_rate(ctx->frame_rate,
106 &code, &ext_n, &ext_d, 0);
108 sh->frame_rate_code = code;
109 se->frame_rate_extension_n = ext_n;
110 se->frame_rate_extension_d = ext_d;
113 if (ctx->video_format >= 0 ||
114 ctx->colour_primaries >= 0 ||
115 ctx->transfer_characteristics >= 0 ||
116 ctx->matrix_coefficients >= 0) {
119 ctx->sequence_display_extension.extension_start_code =
120 MPEG2_START_EXTENSION;
121 ctx->sequence_display_extension.extension_start_code_identifier =
122 MPEG2_EXTENSION_SEQUENCE_DISPLAY;
123 sde = &ctx->sequence_display_extension.data.sequence_display;
125 *sde = (MPEG2RawSequenceDisplayExtension) {
128 .colour_description = 0,
129 .colour_primaries = 2,
130 .transfer_characteristics = 2,
131 .matrix_coefficients = 2,
133 .display_horizontal_size =
134 se->horizontal_size_extension << 12 | sh->horizontal_size_value,
135 .display_vertical_size =
136 se->vertical_size_extension << 12 | sh->vertical_size_value,
139 err = ff_cbs_insert_unit_content(ctx->cbc, frag, se_pos + 1,
140 MPEG2_START_EXTENSION,
141 &ctx->sequence_display_extension,
144 av_log(bsf, AV_LOG_ERROR, "Failed to insert new sequence "
145 "display extension.\n");
150 if (ctx->video_format >= 0)
151 sde->video_format = ctx->video_format;
153 if (ctx->colour_primaries >= 0 ||
154 ctx->transfer_characteristics >= 0 ||
155 ctx->matrix_coefficients >= 0) {
156 sde->colour_description = 1;
158 if (ctx->colour_primaries >= 0)
159 sde->colour_primaries = ctx->colour_primaries;
161 if (ctx->transfer_characteristics >= 0)
162 sde->transfer_characteristics = ctx->transfer_characteristics;
164 if (ctx->matrix_coefficients >= 0)
165 sde->matrix_coefficients = ctx->matrix_coefficients;
172 static int mpeg2_metadata_filter(AVBSFContext *bsf, AVPacket *pkt)
174 MPEG2MetadataContext *ctx = bsf->priv_data;
175 CodedBitstreamFragment *frag = &ctx->fragment;
178 err = ff_bsf_get_packet_ref(bsf, pkt);
182 err = ff_cbs_read_packet(ctx->cbc, frag, pkt);
184 av_log(bsf, AV_LOG_ERROR, "Failed to read packet.\n");
188 err = mpeg2_metadata_update_fragment(bsf, frag);
190 av_log(bsf, AV_LOG_ERROR, "Failed to update frame fragment.\n");
194 err = ff_cbs_write_packet(ctx->cbc, pkt, frag);
196 av_log(bsf, AV_LOG_ERROR, "Failed to write packet.\n");
202 ff_cbs_fragment_reset(ctx->cbc, frag);
205 av_packet_unref(pkt);
210 static int mpeg2_metadata_init(AVBSFContext *bsf)
212 MPEG2MetadataContext *ctx = bsf->priv_data;
213 CodedBitstreamFragment *frag = &ctx->fragment;
216 #define VALIDITY_CHECK(name) do { \
218 av_log(bsf, AV_LOG_ERROR, "The value 0 for %s is " \
219 "forbidden.\n", #name); \
220 return AVERROR(EINVAL); \
223 VALIDITY_CHECK(colour_primaries);
224 VALIDITY_CHECK(transfer_characteristics);
225 VALIDITY_CHECK(matrix_coefficients);
226 #undef VALIDITY_CHECK
228 err = ff_cbs_init(&ctx->cbc, AV_CODEC_ID_MPEG2VIDEO, bsf);
232 if (bsf->par_in->extradata) {
233 err = ff_cbs_read_extradata(ctx->cbc, frag, bsf->par_in);
235 av_log(bsf, AV_LOG_ERROR, "Failed to read extradata.\n");
239 err = mpeg2_metadata_update_fragment(bsf, frag);
241 av_log(bsf, AV_LOG_ERROR, "Failed to update metadata fragment.\n");
245 err = ff_cbs_write_extradata(ctx->cbc, bsf->par_out, frag);
247 av_log(bsf, AV_LOG_ERROR, "Failed to write extradata.\n");
254 ff_cbs_fragment_reset(ctx->cbc, frag);
258 static void mpeg2_metadata_close(AVBSFContext *bsf)
260 MPEG2MetadataContext *ctx = bsf->priv_data;
262 ff_cbs_fragment_free(ctx->cbc, &ctx->fragment);
263 ff_cbs_close(&ctx->cbc);
266 #define OFFSET(x) offsetof(MPEG2MetadataContext, x)
267 #define FLAGS (AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_BSF_PARAM)
268 static const AVOption mpeg2_metadata_options[] = {
269 { "display_aspect_ratio", "Set display aspect ratio (table 6-3)",
270 OFFSET(display_aspect_ratio), AV_OPT_TYPE_RATIONAL,
271 { .dbl = 0.0 }, 0, 65535, FLAGS },
273 { "frame_rate", "Set frame rate",
274 OFFSET(frame_rate), AV_OPT_TYPE_RATIONAL,
275 { .dbl = 0.0 }, 0, UINT_MAX, FLAGS },
277 { "video_format", "Set video format (table 6-6)",
278 OFFSET(video_format), AV_OPT_TYPE_INT,
279 { .i64 = -1 }, -1, 7, FLAGS },
280 { "colour_primaries", "Set colour primaries (table 6-7)",
281 OFFSET(colour_primaries), AV_OPT_TYPE_INT,
282 { .i64 = -1 }, -1, 255, FLAGS },
283 { "transfer_characteristics", "Set transfer characteristics (table 6-8)",
284 OFFSET(transfer_characteristics), AV_OPT_TYPE_INT,
285 { .i64 = -1 }, -1, 255, FLAGS },
286 { "matrix_coefficients", "Set matrix coefficients (table 6-9)",
287 OFFSET(matrix_coefficients), AV_OPT_TYPE_INT,
288 { .i64 = -1 }, -1, 255, FLAGS },
293 static const AVClass mpeg2_metadata_class = {
294 .class_name = "mpeg2_metadata_bsf",
295 .item_name = av_default_item_name,
296 .option = mpeg2_metadata_options,
297 .version = LIBAVUTIL_VERSION_INT,
300 static const enum AVCodecID mpeg2_metadata_codec_ids[] = {
301 AV_CODEC_ID_MPEG2VIDEO, AV_CODEC_ID_NONE,
304 const AVBitStreamFilter ff_mpeg2_metadata_bsf = {
305 .name = "mpeg2_metadata",
306 .priv_data_size = sizeof(MPEG2MetadataContext),
307 .priv_class = &mpeg2_metadata_class,
308 .init = &mpeg2_metadata_init,
309 .close = &mpeg2_metadata_close,
310 .filter = &mpeg2_metadata_filter,
311 .codec_ids = mpeg2_metadata_codec_ids,