1 /*
2 * Copyright (c) 2013 The WebM project authors. All Rights Reserved.
3 *
4 * Use of this source code is governed by a BSD-style license
5 * that can be found in the LICENSE file in the root of the source
6 * tree. An additional intellectual property rights grant can be found
7 * in the file PATENTS. All contributing project authors may
8 * be found in the AUTHORS file in the root of the source tree.
9 */
10
11 #include "./webmdec.h"
12
13 #include <stdarg.h>
14
15 #include "third_party/nestegg/include/nestegg/nestegg.h"
16
nestegg_read_cb(void * buffer,size_t length,void * userdata)17 static int nestegg_read_cb(void *buffer, size_t length, void *userdata) {
18 FILE *f = userdata;
19
20 if (fread(buffer, 1, length, f) < length) {
21 if (ferror(f))
22 return -1;
23 if (feof(f))
24 return 0;
25 }
26 return 1;
27 }
28
nestegg_seek_cb(int64_t offset,int whence,void * userdata)29 static int nestegg_seek_cb(int64_t offset, int whence, void *userdata) {
30 switch (whence) {
31 case NESTEGG_SEEK_SET:
32 whence = SEEK_SET;
33 break;
34 case NESTEGG_SEEK_CUR:
35 whence = SEEK_CUR;
36 break;
37 case NESTEGG_SEEK_END:
38 whence = SEEK_END;
39 break;
40 };
41 return fseek(userdata, (int32_t)offset, whence) ? -1 : 0;
42 }
43
nestegg_tell_cb(void * userdata)44 static int64_t nestegg_tell_cb(void *userdata) {
45 return ftell(userdata);
46 }
47
nestegg_log_cb(nestegg * context,unsigned int severity,char const * format,...)48 static void nestegg_log_cb(nestegg *context,
49 unsigned int severity,
50 char const *format, ...) {
51 va_list ap;
52 va_start(ap, format);
53 vfprintf(stderr, format, ap);
54 fprintf(stderr, "\n");
55 va_end(ap);
56 }
57
file_is_webm(struct WebmInputContext * webm_ctx,struct VpxInputContext * vpx_ctx)58 int file_is_webm(struct WebmInputContext *webm_ctx,
59 struct VpxInputContext *vpx_ctx) {
60 uint32_t i, n;
61 int track_type = -1;
62 int codec_id;
63
64 nestegg_io io = {nestegg_read_cb, nestegg_seek_cb, nestegg_tell_cb, 0};
65 nestegg_video_params params;
66
67 io.userdata = vpx_ctx->file;
68 if (nestegg_init(&webm_ctx->nestegg_ctx, io, NULL, -1))
69 goto fail;
70
71 if (nestegg_track_count(webm_ctx->nestegg_ctx, &n))
72 goto fail;
73
74 for (i = 0; i < n; i++) {
75 track_type = nestegg_track_type(webm_ctx->nestegg_ctx, i);
76
77 if (track_type == NESTEGG_TRACK_VIDEO)
78 break;
79 else if (track_type < 0)
80 goto fail;
81 }
82
83 codec_id = nestegg_track_codec_id(webm_ctx->nestegg_ctx, i);
84 if (codec_id == NESTEGG_CODEC_VP8) {
85 vpx_ctx->fourcc = VP8_FOURCC;
86 } else if (codec_id == NESTEGG_CODEC_VP9) {
87 vpx_ctx->fourcc = VP9_FOURCC;
88 } else {
89 fatal("Not VPx video, quitting.\n");
90 }
91
92 webm_ctx->video_track = i;
93
94 if (nestegg_track_video_params(webm_ctx->nestegg_ctx, i, ¶ms))
95 goto fail;
96
97 vpx_ctx->framerate.denominator = 0;
98 vpx_ctx->framerate.numerator = 0;
99 vpx_ctx->width = params.width;
100 vpx_ctx->height = params.height;
101
102 return 1;
103
104 fail:
105 webm_ctx->nestegg_ctx = NULL;
106 rewind(vpx_ctx->file);
107
108 return 0;
109 }
110
webm_read_frame(struct WebmInputContext * webm_ctx,uint8_t ** buffer,size_t * bytes_in_buffer,size_t * buffer_size)111 int webm_read_frame(struct WebmInputContext *webm_ctx,
112 uint8_t **buffer,
113 size_t *bytes_in_buffer,
114 size_t *buffer_size) {
115 if (webm_ctx->chunk >= webm_ctx->chunks) {
116 uint32_t track;
117
118 do {
119 /* End of this packet, get another. */
120 if (webm_ctx->pkt) {
121 nestegg_free_packet(webm_ctx->pkt);
122 webm_ctx->pkt = NULL;
123 }
124
125 if (nestegg_read_packet(webm_ctx->nestegg_ctx, &webm_ctx->pkt) <= 0 ||
126 nestegg_packet_track(webm_ctx->pkt, &track)) {
127 return 1;
128 }
129 } while (track != webm_ctx->video_track);
130
131 if (nestegg_packet_count(webm_ctx->pkt, &webm_ctx->chunks))
132 return 1;
133
134 webm_ctx->chunk = 0;
135 }
136
137 if (nestegg_packet_data(webm_ctx->pkt, webm_ctx->chunk,
138 buffer, bytes_in_buffer)) {
139 return 1;
140 }
141
142 webm_ctx->chunk++;
143 return 0;
144 }
145
webm_guess_framerate(struct WebmInputContext * webm_ctx,struct VpxInputContext * vpx_ctx)146 int webm_guess_framerate(struct WebmInputContext *webm_ctx,
147 struct VpxInputContext *vpx_ctx) {
148 uint32_t i;
149 uint64_t tstamp = 0;
150
151 /* Check to see if we can seek before we parse any data. */
152 if (nestegg_track_seek(webm_ctx->nestegg_ctx, webm_ctx->video_track, 0)) {
153 warn("Failed to guess framerate (no Cues), set to 30fps.\n");
154 vpx_ctx->framerate.numerator = 30;
155 vpx_ctx->framerate.denominator = 1;
156 return 0;
157 }
158
159 /* Guess the framerate. Read up to 1 second, or 50 video packets,
160 * whichever comes first.
161 */
162 for (i = 0; tstamp < 1000000000 && i < 50;) {
163 nestegg_packet *pkt;
164 uint32_t track;
165
166 if (nestegg_read_packet(webm_ctx->nestegg_ctx, &pkt) <= 0)
167 break;
168
169 nestegg_packet_track(pkt, &track);
170 if (track == webm_ctx->video_track) {
171 nestegg_packet_tstamp(pkt, &tstamp);
172 ++i;
173 }
174
175 nestegg_free_packet(pkt);
176 }
177
178 if (nestegg_track_seek(webm_ctx->nestegg_ctx, webm_ctx->video_track, 0))
179 goto fail;
180
181 vpx_ctx->framerate.numerator = (i - 1) * 1000000;
182 vpx_ctx->framerate.denominator = (int)(tstamp / 1000);
183 return 0;
184
185 fail:
186 nestegg_destroy(webm_ctx->nestegg_ctx);
187 webm_ctx->nestegg_ctx = NULL;
188 rewind(vpx_ctx->file);
189 return 1;
190 }
191
webm_free(struct WebmInputContext * webm_ctx)192 void webm_free(struct WebmInputContext *webm_ctx) {
193 if (webm_ctx && webm_ctx->nestegg_ctx) {
194 if (webm_ctx->pkt)
195 nestegg_free_packet(webm_ctx->pkt);
196 nestegg_destroy(webm_ctx->nestegg_ctx);
197 }
198 }
199