| 87 | } |
| 88 | |
| 89 | static int gif_write_packet(AVFormatContext *s, AVPacket *new_pkt) |
| 90 | { |
| 91 | GIFContext *gif = s->priv_data; |
| 92 | AVIOContext *pb = s->pb; |
| 93 | AVPacket *pkt = gif->prev_pkt; |
| 94 | |
| 95 | if (!gif->prev_pkt) { |
| 96 | gif->prev_pkt = av_packet_alloc(); |
| 97 | if (!gif->prev_pkt) |
| 98 | return AVERROR(ENOMEM); |
| 99 | return av_packet_ref(gif->prev_pkt, new_pkt); |
| 100 | } |
| 101 | |
| 102 | gif->last_pos = avio_tell(pb); |
| 103 | if (pkt->size > 0) |
| 104 | gif->have_end = pkt->data[pkt->size - 1] == GIF_TRAILER; |
| 105 | |
| 106 | if (!gif->last_pos) { |
| 107 | int delay_pos; |
| 108 | int off = 13; |
| 109 | |
| 110 | if (pkt->size < 13) |
| 111 | return AVERROR(EINVAL); |
| 112 | |
| 113 | if (pkt->data[10] & 0x80) |
| 114 | off += 3 * (1 << ((pkt->data[10] & 0x07) + 1)); |
| 115 | |
| 116 | if (pkt->size < off + 2) |
| 117 | return AVERROR(EINVAL); |
| 118 | |
| 119 | avio_write(pb, pkt->data, off); |
| 120 | |
| 121 | if (pkt->data[off] == GIF_EXTENSION_INTRODUCER && pkt->data[off + 1] == 0xff) |
| 122 | off += 19; |
| 123 | |
| 124 | if (pkt->size <= off) |
| 125 | return AVERROR(EINVAL); |
| 126 | |
| 127 | /* "NETSCAPE EXTENSION" for looped animation GIF */ |
| 128 | if (gif->loop >= 0) { |
| 129 | avio_w8(pb, GIF_EXTENSION_INTRODUCER); /* GIF Extension code */ |
| 130 | avio_w8(pb, GIF_APP_EXT_LABEL); /* Application Extension Label */ |
| 131 | avio_w8(pb, 0x0b); /* Length of Application Block */ |
| 132 | avio_write(pb, "NETSCAPE2.0", sizeof("NETSCAPE2.0") - 1); |
| 133 | avio_w8(pb, 0x03); /* Length of Data Sub-Block */ |
| 134 | avio_w8(pb, 0x01); |
| 135 | avio_wl16(pb, (uint16_t)gif->loop); |
| 136 | avio_w8(pb, 0x00); /* Data Sub-block Terminator */ |
| 137 | } |
| 138 | |
| 139 | delay_pos = gif_parse_packet(s, pkt->data + off, pkt->size - off); |
| 140 | if (delay_pos > 0 && delay_pos < pkt->size - off - 2) { |
| 141 | avio_write(pb, pkt->data + off, delay_pos); |
| 142 | avio_wl16(pb, gif_get_delay(gif, pkt, new_pkt)); |
| 143 | avio_write(pb, pkt->data + off + delay_pos + 2, pkt->size - off - delay_pos - 2); |
| 144 | } else { |
| 145 | avio_write(pb, pkt->data + off, pkt->size - off); |
| 146 | } |
no test coverage detected