2 * H.264 MP4 to Annex B byte stream format filter
3 * Copyright (c) 2007 Benoit Fouet <benoit.fouet@free.fr>
5 * This file is part of Libav.
7 * Libav 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.
12 * Libav 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.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with Libav; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
24 #include "libavutil/intreadwrite.h"
25 #include "libavutil/mem.h"
30 typedef struct H264BSFContext {
36 static int alloc_and_copy(AVPacket *out,
37 const uint8_t *sps_pps, uint32_t sps_pps_size,
38 const uint8_t *in, uint32_t in_size)
40 uint32_t offset = out->size;
41 uint8_t nal_header_size = offset ? 3 : 4;
44 err = av_grow_packet(out, sps_pps_size + in_size + nal_header_size);
49 memcpy(out->data + offset, sps_pps, sps_pps_size);
50 memcpy(out->data + sps_pps_size + nal_header_size + offset, in, in_size);
52 AV_WB32(out->data + sps_pps_size, 1);
54 (out->data + offset + sps_pps_size)[0] =
55 (out->data + offset + sps_pps_size)[1] = 0;
56 (out->data + offset + sps_pps_size)[2] = 1;
62 static int h264_extradata_to_annexb(AVBSFContext *ctx, const int padding)
65 uint64_t total_size = 0;
66 uint8_t *out = NULL, unit_nb, sps_done = 0,
67 sps_seen = 0, pps_seen = 0;
68 const uint8_t *extradata = ctx->par_in->extradata + 4;
69 static const uint8_t nalu_header[4] = { 0, 0, 0, 1 };
70 int length_size = (*extradata++ & 0x3) + 1; // retrieve length coded size
73 return AVERROR(EINVAL);
75 /* retrieve sps and pps unit(s) */
76 unit_nb = *extradata++ & 0x1f; /* number of sps unit(s) */
78 unit_nb = *extradata++; /* number of pps unit(s) */
90 unit_size = AV_RB16(extradata);
91 total_size += unit_size + 4;
92 if (total_size > INT_MAX - padding ||
93 extradata + 2 + unit_size > ctx->par_in->extradata +
94 ctx->par_in->extradata_size) {
96 return AVERROR(EINVAL);
98 if ((err = av_reallocp(&out, total_size + padding)) < 0)
100 memcpy(out + total_size - unit_size - 4, nalu_header, 4);
101 memcpy(out + total_size - unit_size, extradata + 2, unit_size);
102 extradata += 2 + unit_size;
104 if (!unit_nb && !sps_done++) {
105 unit_nb = *extradata++; /* number of pps unit(s) */
112 memset(out + total_size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
115 av_log(ctx, AV_LOG_WARNING,
116 "Warning: SPS NALU missing or invalid. "
117 "The resulting stream may not play.\n");
120 av_log(ctx, AV_LOG_WARNING,
121 "Warning: PPS NALU missing or invalid. "
122 "The resulting stream may not play.\n");
124 av_freep(&ctx->par_out->extradata);
125 ctx->par_out->extradata = out;
126 ctx->par_out->extradata_size = total_size;
131 static int h264_mp4toannexb_init(AVBSFContext *ctx)
133 H264BSFContext *s = ctx->priv_data;
136 /* retrieve sps and pps NAL units from extradata */
137 if (ctx->par_in->extradata_size >= 6) {
138 ret = h264_extradata_to_annexb(ctx, AV_INPUT_BUFFER_PADDING_SIZE);
142 s->length_size = ret;
144 s->extradata_parsed = 1;
150 static int h264_mp4toannexb_filter(AVBSFContext *ctx, AVPacket *out)
152 H264BSFContext *s = ctx->priv_data;
157 uint32_t cumul_size = 0;
159 const uint8_t *buf_end;
163 ret = ff_bsf_get_packet(ctx, &in);
167 /* nothing to filter */
168 if (!s->extradata_parsed) {
169 av_packet_move_ref(out, in);
176 buf_end = in->data + in->size;
179 if (buf + s->length_size > buf_end)
182 if (s->length_size == 1) {
184 } else if (s->length_size == 2) {
185 nal_size = AV_RB16(buf);
187 nal_size = AV_RB32(buf);
189 buf += s->length_size;
190 unit_type = *buf & 0x1f;
192 if (buf + nal_size > buf_end || nal_size < 0)
195 /* prepend only to the first type 5 NAL unit of an IDR picture */
196 if (s->first_idr && unit_type == 5) {
197 if (alloc_and_copy(out,
198 ctx->par_out->extradata, ctx->par_out->extradata_size,
203 if (alloc_and_copy(out,
204 NULL, 0, buf, nal_size) < 0)
206 if (!s->first_idr && unit_type == 1)
211 cumul_size += nal_size + s->length_size;
212 } while (cumul_size < buf_size);
214 ret = av_packet_copy_props(out, in);
220 av_packet_unref(out);
226 static const enum AVCodecID codec_ids[] = {
227 AV_CODEC_ID_H264, AV_CODEC_ID_NONE,
230 const AVBitStreamFilter ff_h264_mp4toannexb_bsf = {
231 .name = "h264_mp4toannexb",
232 .priv_data_size = sizeof(H264BSFContext),
233 .init = h264_mp4toannexb_init,
234 .filter = h264_mp4toannexb_filter,
235 .codec_ids = codec_ids,