1 /*****************************************************************************
2 * mp4.c: mp4 muxer
3 *****************************************************************************
4 * Copyright (C) 2003-2021 x264 project
5 *
6 * Authors: Laurent Aimar <fenrir@via.ecp.fr>
7 * Loren Merritt <lorenm@u.washington.edu>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02111, USA.
22 *
23 * This program is also available under a commercial proprietary license.
24 * For more information, contact us at licensing@x264.com.
25 *****************************************************************************/
26
27 #include "output.h"
28 #include <gpac/isomedia.h>
29
30 typedef struct
31 {
32 GF_ISOFile *p_file;
33 GF_AVCConfig *p_config;
34 GF_ISOSample *p_sample;
35 int i_track;
36 uint32_t i_descidx;
37 uint64_t i_time_res;
38 int64_t i_time_inc;
39 int64_t i_delay_time;
40 int64_t i_init_delta;
41 int i_numframe;
42 int i_delay_frames;
43 int b_dts_compress;
44 int i_dts_compress_multiplier;
45 int i_data_size;
46 } mp4_hnd_t;
47
recompute_bitrate_mp4(GF_ISOFile * p_file,int i_track)48 static void recompute_bitrate_mp4( GF_ISOFile *p_file, int i_track )
49 {
50 u32 count, di, timescale, time_wnd, rate;
51 u64 offset;
52 Double br;
53 GF_ESD *esd;
54
55 esd = gf_isom_get_esd( p_file, i_track, 1 );
56 if( !esd )
57 return;
58
59 esd->decoderConfig->avgBitrate = 0;
60 esd->decoderConfig->maxBitrate = 0;
61 rate = time_wnd = 0;
62
63 timescale = gf_isom_get_media_timescale( p_file, i_track );
64 count = gf_isom_get_sample_count( p_file, i_track );
65 for( u32 i = 0; i < count; i++ )
66 {
67 GF_ISOSample *samp = gf_isom_get_sample_info( p_file, i_track, i+1, &di, &offset );
68 if( !samp )
69 {
70 x264_cli_log( "mp4", X264_LOG_ERROR, "failure reading back frame %u\n", i );
71 break;
72 }
73
74 if( esd->decoderConfig->bufferSizeDB < samp->dataLength )
75 esd->decoderConfig->bufferSizeDB = samp->dataLength;
76
77 esd->decoderConfig->avgBitrate += samp->dataLength;
78 rate += samp->dataLength;
79 if( samp->DTS > time_wnd + timescale )
80 {
81 if( rate > esd->decoderConfig->maxBitrate )
82 esd->decoderConfig->maxBitrate = rate;
83 time_wnd = samp->DTS;
84 rate = 0;
85 }
86
87 gf_isom_sample_del( &samp );
88 }
89
90 br = (Double)(s64)gf_isom_get_media_duration( p_file, i_track );
91 br /= timescale;
92 esd->decoderConfig->avgBitrate = (u32)(esd->decoderConfig->avgBitrate / br);
93 /*move to bps*/
94 esd->decoderConfig->avgBitrate *= 8;
95 esd->decoderConfig->maxBitrate *= 8;
96
97 gf_isom_change_mpeg4_description( p_file, i_track, 1, esd );
98 gf_odf_desc_del( (GF_Descriptor*)esd );
99 }
100
close_file(hnd_t handle,int64_t largest_pts,int64_t second_largest_pts)101 static int close_file( hnd_t handle, int64_t largest_pts, int64_t second_largest_pts )
102 {
103 mp4_hnd_t *p_mp4 = handle;
104
105 if( !p_mp4 )
106 return 0;
107
108 if( p_mp4->p_config )
109 gf_odf_avc_cfg_del( p_mp4->p_config );
110
111 if( p_mp4->p_sample )
112 {
113 if( p_mp4->p_sample->data )
114 free( p_mp4->p_sample->data );
115
116 p_mp4->p_sample->dataLength = 0;
117 gf_isom_sample_del( &p_mp4->p_sample );
118 }
119
120 if( p_mp4->p_file )
121 {
122 if( p_mp4->i_track )
123 {
124 /* The mdhd duration is defined as CTS[final] - CTS[0] + duration of last frame.
125 * The mdhd duration (in seconds) should be able to be longer than the tkhd duration since the track is managed by edts.
126 * So, if mdhd duration is equal to the last DTS or less, we give the last composition time delta to the last sample duration.
127 * And then, the mdhd duration is updated, but it time-wise doesn't give the actual duration.
128 * The tkhd duration is the actual track duration. */
129 uint64_t mdhd_duration = (2 * largest_pts - second_largest_pts) * p_mp4->i_time_inc;
130 if( mdhd_duration != gf_isom_get_media_duration( p_mp4->p_file, p_mp4->i_track ) )
131 {
132 uint64_t last_dts = gf_isom_get_sample_dts( p_mp4->p_file, p_mp4->i_track, p_mp4->i_numframe );
133 uint32_t last_duration = (uint32_t)( mdhd_duration > last_dts ? mdhd_duration - last_dts : (largest_pts - second_largest_pts) * p_mp4->i_time_inc );
134 gf_isom_set_last_sample_duration( p_mp4->p_file, p_mp4->i_track, last_duration );
135 }
136
137 /* Write an Edit Box if the first CTS offset is positive.
138 * A media_time is given by not the mvhd timescale but rather the mdhd timescale.
139 * The reason is that an Edit Box maps the presentation time-line to the media time-line.
140 * Any demuxers should follow the Edit Box if it exists. */
141 GF_ISOSample *sample = gf_isom_get_sample_info( p_mp4->p_file, p_mp4->i_track, 1, NULL, NULL );
142 if( sample && sample->CTS_Offset > 0 )
143 {
144 uint32_t mvhd_timescale = gf_isom_get_timescale( p_mp4->p_file );
145 uint64_t tkhd_duration = (uint64_t)( mdhd_duration * ( (double)mvhd_timescale / p_mp4->i_time_res ) );
146 #if GPAC_VERSION_MAJOR > 8
147 gf_isom_append_edit( p_mp4->p_file, p_mp4->i_track, tkhd_duration, sample->CTS_Offset, GF_ISOM_EDIT_NORMAL );
148 #else
149 gf_isom_append_edit_segment( p_mp4->p_file, p_mp4->i_track, tkhd_duration, sample->CTS_Offset, GF_ISOM_EDIT_NORMAL );
150 #endif
151 }
152 gf_isom_sample_del( &sample );
153
154 recompute_bitrate_mp4( p_mp4->p_file, p_mp4->i_track );
155 }
156 gf_isom_set_pl_indication( p_mp4->p_file, GF_ISOM_PL_VISUAL, 0x15 );
157 gf_isom_set_storage_mode( p_mp4->p_file, GF_ISOM_STORE_FLAT );
158 gf_isom_close( p_mp4->p_file );
159 }
160
161 free( p_mp4 );
162
163 return 0;
164 }
165
open_file(char * psz_filename,hnd_t * p_handle,cli_output_opt_t * opt)166 static int open_file( char *psz_filename, hnd_t *p_handle, cli_output_opt_t *opt )
167 {
168 *p_handle = NULL;
169 FILE *fh = x264_fopen( psz_filename, "w" );
170 if( !fh )
171 return -1;
172 int b_regular = x264_is_regular_file( fh );
173 fclose( fh );
174 FAIL_IF_ERR( !b_regular, "mp4", "MP4 output is incompatible with non-regular file `%s'\n", psz_filename );
175
176 mp4_hnd_t *p_mp4 = calloc( 1, sizeof(mp4_hnd_t) );
177 if( !p_mp4 )
178 return -1;
179
180 p_mp4->p_file = gf_isom_open( psz_filename, GF_ISOM_OPEN_WRITE, NULL );
181 p_mp4->b_dts_compress = opt->use_dts_compress;
182
183 if( !(p_mp4->p_sample = gf_isom_sample_new()) )
184 {
185 close_file( p_mp4, 0, 0 );
186 return -1;
187 }
188
189 gf_isom_set_brand_info( p_mp4->p_file, GF_ISOM_BRAND_AVC1, 0 );
190
191 *p_handle = p_mp4;
192
193 return 0;
194 }
195
set_param(hnd_t handle,x264_param_t * p_param)196 static int set_param( hnd_t handle, x264_param_t *p_param )
197 {
198 mp4_hnd_t *p_mp4 = handle;
199
200 p_mp4->i_delay_frames = p_param->i_bframe ? (p_param->i_bframe_pyramid ? 2 : 1) : 0;
201 p_mp4->i_dts_compress_multiplier = p_mp4->b_dts_compress * p_mp4->i_delay_frames + 1;
202
203 p_mp4->i_time_res = (uint64_t)p_param->i_timebase_den * p_mp4->i_dts_compress_multiplier;
204 p_mp4->i_time_inc = (uint64_t)p_param->i_timebase_num * p_mp4->i_dts_compress_multiplier;
205 FAIL_IF_ERR( p_mp4->i_time_res > UINT32_MAX, "mp4", "MP4 media timescale %"PRIu64" exceeds maximum\n", p_mp4->i_time_res );
206
207 p_mp4->i_track = gf_isom_new_track( p_mp4->p_file, 0, GF_ISOM_MEDIA_VISUAL,
208 p_mp4->i_time_res );
209
210 p_mp4->p_config = gf_odf_avc_cfg_new();
211 gf_isom_avc_config_new( p_mp4->p_file, p_mp4->i_track, p_mp4->p_config,
212 NULL, NULL, &p_mp4->i_descidx );
213
214 gf_isom_set_track_enabled( p_mp4->p_file, p_mp4->i_track, 1 );
215
216 gf_isom_set_visual_info( p_mp4->p_file, p_mp4->i_track, p_mp4->i_descidx,
217 p_param->i_width, p_param->i_height );
218
219 if( p_param->vui.i_sar_width && p_param->vui.i_sar_height )
220 {
221 uint64_t dw = p_param->i_width << 16;
222 uint64_t dh = p_param->i_height << 16;
223 double sar = (double)p_param->vui.i_sar_width / p_param->vui.i_sar_height;
224 if( sar > 1.0 )
225 dw *= sar;
226 else
227 dh /= sar;
228 gf_isom_set_pixel_aspect_ratio( p_mp4->p_file, p_mp4->i_track, p_mp4->i_descidx, p_param->vui.i_sar_width, p_param->vui.i_sar_height, 0 );
229 gf_isom_set_track_layout_info( p_mp4->p_file, p_mp4->i_track, dw, dh, 0, 0, 0 );
230 }
231
232 p_mp4->i_data_size = p_param->i_width * p_param->i_height * 3 / 2;
233 p_mp4->p_sample->data = malloc( p_mp4->i_data_size );
234 if( !p_mp4->p_sample->data )
235 {
236 p_mp4->i_data_size = 0;
237 return -1;
238 }
239
240 return 0;
241 }
242
check_buffer(mp4_hnd_t * p_mp4,int needed_size)243 static int check_buffer( mp4_hnd_t *p_mp4, int needed_size )
244 {
245 if( needed_size > p_mp4->i_data_size )
246 {
247 void *ptr = realloc( p_mp4->p_sample->data, needed_size );
248 if( !ptr )
249 return -1;
250 p_mp4->p_sample->data = ptr;
251 p_mp4->i_data_size = needed_size;
252 }
253 return 0;
254 }
255
write_headers(hnd_t handle,x264_nal_t * p_nal)256 static int write_headers( hnd_t handle, x264_nal_t *p_nal )
257 {
258 mp4_hnd_t *p_mp4 = handle;
259 GF_AVCConfigSlot *p_slot;
260
261 int sps_size = p_nal[0].i_payload - 4;
262 int pps_size = p_nal[1].i_payload - 4;
263 int sei_size = p_nal[2].i_payload;
264
265 uint8_t *sps = p_nal[0].p_payload + 4;
266 uint8_t *pps = p_nal[1].p_payload + 4;
267 uint8_t *sei = p_nal[2].p_payload;
268
269 // SPS
270
271 p_mp4->p_config->configurationVersion = 1;
272 p_mp4->p_config->AVCProfileIndication = sps[1];
273 p_mp4->p_config->profile_compatibility = sps[2];
274 p_mp4->p_config->AVCLevelIndication = sps[3];
275 p_slot = malloc( sizeof(GF_AVCConfigSlot) );
276 if( !p_slot )
277 return -1;
278 p_slot->size = sps_size;
279 p_slot->data = malloc( p_slot->size );
280 if( !p_slot->data )
281 return -1;
282 memcpy( p_slot->data, sps, sps_size );
283 gf_list_add( p_mp4->p_config->sequenceParameterSets, p_slot );
284
285 // PPS
286
287 p_slot = malloc( sizeof(GF_AVCConfigSlot) );
288 if( !p_slot )
289 return -1;
290 p_slot->size = pps_size;
291 p_slot->data = malloc( p_slot->size );
292 if( !p_slot->data )
293 return -1;
294 memcpy( p_slot->data, pps, pps_size );
295 gf_list_add( p_mp4->p_config->pictureParameterSets, p_slot );
296 gf_isom_avc_config_update( p_mp4->p_file, p_mp4->i_track, 1, p_mp4->p_config );
297
298 // SEI
299
300 if( check_buffer( p_mp4, p_mp4->p_sample->dataLength + sei_size ) )
301 return -1;
302 memcpy( p_mp4->p_sample->data + p_mp4->p_sample->dataLength, sei, sei_size );
303 p_mp4->p_sample->dataLength += sei_size;
304
305 return sei_size + sps_size + pps_size;
306 }
307
write_frame(hnd_t handle,uint8_t * p_nalu,int i_size,x264_picture_t * p_picture)308 static int write_frame( hnd_t handle, uint8_t *p_nalu, int i_size, x264_picture_t *p_picture )
309 {
310 mp4_hnd_t *p_mp4 = handle;
311 int64_t dts;
312 int64_t cts;
313
314 if( check_buffer( p_mp4, p_mp4->p_sample->dataLength + i_size ) )
315 return -1;
316 memcpy( p_mp4->p_sample->data + p_mp4->p_sample->dataLength, p_nalu, i_size );
317 p_mp4->p_sample->dataLength += i_size;
318
319 if( !p_mp4->i_numframe )
320 p_mp4->i_delay_time = p_picture->i_dts * -1;
321
322 if( p_mp4->b_dts_compress )
323 {
324 if( p_mp4->i_numframe == 1 )
325 p_mp4->i_init_delta = (p_picture->i_dts + p_mp4->i_delay_time) * p_mp4->i_time_inc;
326 dts = p_mp4->i_numframe > p_mp4->i_delay_frames
327 ? p_picture->i_dts * p_mp4->i_time_inc
328 : p_mp4->i_numframe * (p_mp4->i_init_delta / p_mp4->i_dts_compress_multiplier);
329 cts = p_picture->i_pts * p_mp4->i_time_inc;
330 }
331 else
332 {
333 dts = (p_picture->i_dts + p_mp4->i_delay_time) * p_mp4->i_time_inc;
334 cts = (p_picture->i_pts + p_mp4->i_delay_time) * p_mp4->i_time_inc;
335 }
336
337 p_mp4->p_sample->IsRAP = p_picture->b_keyframe;
338 p_mp4->p_sample->DTS = dts;
339 p_mp4->p_sample->CTS_Offset = (uint32_t)(cts - dts);
340 gf_isom_add_sample( p_mp4->p_file, p_mp4->i_track, p_mp4->i_descidx, p_mp4->p_sample );
341
342 p_mp4->p_sample->dataLength = 0;
343 p_mp4->i_numframe++;
344
345 return i_size;
346 }
347
348 const cli_output_t mp4_output = { open_file, set_param, write_headers, write_frame, close_file };
349